Free Perl Reference Book

This is just a preview what's inside PERL reference book if you want full pdf file feel free to email me at programmingbooks4@gmail.com Language Version Release Notes Release Date 1.000 1987-12-18 2.000 1988-06-05 3.000 1989-10-18 4.000 1991-03-21 5.000 1994-10-17 5.001 1995-05-13 5.002 1996-02-29 5.003 1996-06-25 5.004 perl5004delta 1997-05-15 5.005 perl5005delta 1998-07-22 5.6.0 perl56delta 2000-03-22 5.8.0 perl58delta 2002-07-18 5.8.8 perl581delta, perl582delta, perl583delta, perl584delta, perl585delta, perl586delta, perl587delta, perl588delta 2006-02-01 5.10.0 perl5100delta 2007-12-18 5.12.0 perl5120delta 2010-04-12 5.14.0 perl5140delta 2011-05-14 5.16.0 perl5160delta 2012-05-20 5.18.0 perl5180delta 2013-05-18 5.20.0 perl5200delta 2014-05-27 5.22.0 perl5220delta 2015-06-01 5.24.0 perl5240delta 2016-05-09 5.26.0 perl5260delta 2017-05-30 Section 1.1: Getting started with Perl Perl tries to do what you mean: print "Hello World\n"; The two tricky bits are the semicolon at the end of the line and the \n, which adds a newline (line feed). If you have a relatively new version of perl, you can use say instead of print to have the carriage return added automatically: Version ≥ 5.10.0 use feature 'say'; say "Hello World"; The say feature is also enabled automatically with a use v5.10 (or higher) declaration: use v5.10; GoalKicker.com – Perl® Notes for Professionals 3 say "Hello World"; It's pretty common to just use perl on the command line using the -e option: $ perl -e 'print "Hello World\n"' Hello World Adding the -l option is one way to print newlines automatically: $ perl -le 'print "Hello World"' Hello World Version ≥ 5.10.0 If you want to enable new features, use the -E option instead: $ perl -E 'say "Hello World"' Hello World You can also, of course, save the script in a file. Just remove the -e command line option and use the filename of the script: perl script.pl. For programs longer than a line, it's wise to turn on a couple of options: use strict; use warnings; print "Hello World\n"; There's no real disadvantage other than making the code slightly longer. In exchange, the strict pragma prevents you from using code that is potentially unsafe and warnings notifies you of many common errors. Notice the line-ending semicolon is optional for the last line, but is a good idea in case you later add to the end of your code. For more options how to run Perl, see perlrun or type perldoc perlrun at a command prompt. For a more detailed introduction to Perl, see perlintro or type perldoc perlintro at a command prompt. For a quirky interactive tutorial, Try Perl. GoalKicker.com – Perl® Notes for Professionals 4 Chapter 2: Comments Section 2.1: Single-line comments Single-line comments begin with a pound sign # and go to the end of the line: # This is a comment my $foo = "bar"; # This is also a comment Section 2.2: Multi-line comments Multi-line comments start with = and with the =cut statement. These are special comments called POD (Plain Old Documentation). Any text between the markers will be commented out: =begin comment This is another comment. And it spans multiple lines! =end comment =cut GoalKicker.com – Perl® Notes for Professionals 5 Chapter 3: Variables Section 3.1: Scalars Scalars are Perl's most basic data type. They're marked with the sigil $ and hold a single value of one of three types: a number (3, 42, 3.141, etc.) a string ('hi', "abc", etc.) a reference to a variable (see other examples). my $integer = 3; # number my $string = "Hello World"; # string my $reference = \$string; # reference to $string Perl converts between numbers and strings on the fly, based on what a particular operator expects. my $number = '41'; # string '41' my $meaning = $number + 1; # number 42 my $sadness = '20 apples'; # string '20 apples' my $danger = $sadness * 2; # number '40', raises warning When converting a string into a number, Perl takes as many digits from the front of a string as it can – hence why 20 apples is converted into 20 in the last line. Based on whether you want to treat the contents of a scalar as a string or a number, you need to use different operators. Do not mix them. # String comparison # Number comparison 'Potato' eq 'Potato'; 42 == 42; 'Potato' ne 'Pomato'; 42 != 24; 'Camel' lt 'Potato'; 41 < 42; 'Zombie' gt 'Potato'; 43 > 42; # String concatenation # Number summation 'Banana' . 'phone'; 23 + 19; # String repetition # Number multiplication 'nan' x 3; 6 * 7; Attempting to use string operations on numbers will not raise warnings; attempting to use number operations on non-numeric strings will. Do be aware that some non-digit strings such as 'inf', 'nan', '0 but true' count as numbers. Section 3.2: Array References Array References are scalars ($) which refer to Arrays. my @array = ("Hello"); # Creating array, assigning value from a list my $array_reference = \@array; These can be created more short-hand as follows: my $other_array_reference = ["Hello"]; Modifying / Using array references require dereferencing them first.

Free Ruby Reference Book

This is just a preview what's inside RUBY reference book if you want full pdf file feel free to email me at programmingbooks4@gmail.com Chapter 1: Getting started with Ruby Language Version Release Date 2.5.1 2018-03-28 2.4 2016-12-25 2.3 2015-12-25 2.2 2014-12-25 2.1 2013-12-25 2.0 2013-02-24 1.9 2007-12-25 1.8 2003-08-04 1.6.8 2002-12-24 Section 1.1: Hello World This example assumes Ruby is installed. Place the following in a file named hello.rb: puts 'Hello World' From the command line, type the following command to execute the Ruby code from the source file: $ ruby hello.rb This should output: Hello World The output will be immediately displayed to the console. Ruby source files don't need to be compiled before being executed. The Ruby interpreter compiles and executes the Ruby file at runtime. Section 1.2: Hello World as a Self-Executable File—using Shebang (Unix-like operating systems only) You can add an interpreter directive (shebang) to your script. Create a file called hello_world.rb which contains: #!/usr/bin/env ruby puts 'Hello World!' Give the script executable permissions. Here's how to do that in Unix: $ chmod u+x hello_world.rb Now you do not need to call the Ruby interpreter explicitly to run your script. $ ./hello_world.rb GoalKicker.com – Ruby® Notes for Professionals 3 Section 1.3: Hello World from IRB Alternatively, you can use the Interactive Ruby Shell (IRB) to immediately execute the Ruby statements you previously wrote in the Ruby file. Start an IRB session by typing: $ irb Then enter the following command: puts "Hello World" This results in the following console output (including newline): Hello World If you don't want to start a new line, you can use print: print "Hello World" Section 1.4: Hello World without source files Run the command below in a shell after installing Ruby. This shows how you can execute simple Ruby programs without creating a Ruby file: ruby -e 'puts "Hello World"' You can also feed a Ruby program to the interpreter's standard input. One way to do that is to use a here document in your shell command: ruby < Section 1.5: Hello World with tk Tk is the standard graphical user interface (GUI) for Ruby. It provides a cross-platform GUI for Ruby programs. Example code: require "tk" TkRoot.new{ title "Hello World!" } Tk.mainloop The result: GoalKicker.com – Ruby® Notes for Professionals 4 Step by Step explanation: require "tk" Load the tk package. TkRoot.new{ title "Hello World!" } Define a widget with the title Hello World Tk.mainloop Start the main loop and display the widget. Section 1.6: My First Method Overview Create a new file named my_first_method.rb Place the following code inside the file: def hello_world puts "Hello world!" end hello_world() # or just 'hello_world' (without parenthesis) Now, from a command line, execute the following: ruby my_first_method.rb The output should be: Hello world! Explanation def is a keyword that tells us that we're def-ining a method - in this case, hello_world is the name of our method. puts "Hello world!" puts (or pipes to the console) the string Hello world! end is a keyword that signifies we're ending our definition of the hello_world method GoalKicker.com – Ruby® Notes for Professionals 5 as the hello_world method doesn't accept any arguments, you can omit the parenthesis by invoking the method GoalKicker.com – Ruby® Notes for Professionals 6 Chapter 2: Casting (type conversion) Section 2.1: Casting to a Float "123.50".to_f #=> 123.5 Float("123.50") #=> 123.5 However, there is a difference when the string is not a valid Float: "something".to_f #=> 0.0 Float("something") # ArgumentError: invalid value for Float(): "something" Section 2.2: Casting to a String 123.5.to_s #=> "123.5" String(123.5) #=> "123.5" Usually, String() will just call #to_s. Methods Kernel#sprintf and String#% behave similar to C: sprintf("%s", 123.5) #=> "123.5" "%s" % 123.5 #=> "123.5" "%d" % 123.5 #=> "123" "%.2f" % 123.5 #=> "123.50" Section 2.3: Casting to an Integer "123.50".to_i #=> 123 Integer("123.50") #=> 123 A string will take the value of any integer at its start, but will not take integers from anywhere else: "123-foo".to_i # => 123 "foo-123".to_i # => 0 However, there is a difference when the string is not a valid Integer: "something".to_i #=> 0 Integer("something") # ArgumentError: invalid value for Integer(): "something" Section 2.4: Floats and Integers 1/2 #=> 0 Since we are dividing two integers, the result is an integer. To solve this problem, we need to cast at least one of those to Float: 1.0 / 2 #=> 0.5 1.to_f / 2 #=> 0.5 1 / Float(2) #=> 0.5 Alternatively, fdiv may be used to return the floating point result of division without explicitly casting either

Free Java Reference Book

This is just a preview what's inside the JAVA refrencebook if you want the full pdf file feel free to email me at programmingbooks4@gmail.com Chapter 1: Getting started with Java Language Java SE Version Code Name End-of-life (free1) Release Date Java SE 10 (Early Access) None future 2018-03-20 Java SE 9 None future 2017-07-27 Java SE 8 Spider future 2014-03-18 Java SE 7 Dolphin 2015-04-14 2011-07-28 Java SE 6 Mustang 2013-04-16 2006-12-23 Java SE 5 Tiger 2009-11-04 2004-10-04 Java SE 1.4 Merlin prior to 2009-11-04 2002-02-06 Java SE 1.3 Kestrel prior to 2009-11-04 2000-05-08 Java SE 1.2 Playground prior to 2009-11-04 1998-12-08 Java SE 1.1 None prior to 2009-11-04 1997-02-19 Java SE 1.0 Oak prior to 2009-11-04 1996-01-21 Section 1.1: Creating Your First Java Program Create a new file in your text editor or IDE named HelloWorld.java. Then paste this code block into the file and save: public class HelloWorld { public static void main(String[] args) { System.out.println("Hello, World!"); } } Run live on Ideone Note: For Java to recognize this as a public class (and not throw a compile time error), the filename must be the same as the class name (HelloWorld in this example) with a .java extension. There should also be a public access modifier before it. Naming conventions recommend that Java classes begin with an uppercase character, and be in camel case format (in which the first letter of each word is capitalized). The conventions recommend against underscores (_) and dollar signs ($). To compile, open a terminal window and navigate to the directory of HelloWorld.java: cd /path/to/containing/folder/ Note: cd is the terminal command to change directory. Enter javac followed by the file name and extension as follows: $ javac HelloWorld.java It's fairly common to get the error 'javac' is not recognized as an internal or external command, operable program or batch file. even when you have installed the JDK and are able to run the program from IDE ex. eclipse etc. Since the path is not added to the environment by default. GoalKicker.com – Java® Notes for Professionals 3 In case you get this on windows, to resolve, first try browsing to your javac.exe path, it's most probably in your C:\Program Files\Java\jdk(version number)\bin. Then try running it with below. $ C:\Program Files\Java\jdk(version number)\bin\javac HelloWorld.java Previously when we were calling javac it was same as above command. Only in that case your OS knew where javac resided. So let's tell it now, this way you don't have to type the whole path every-time. We would need to add this to our PATH To edit the PATH environment variable in Windows XP/Vista/7/8/10: Control Panel ⇒ System ⇒ Advanced system settings Switch to "Advanced" tab ⇒ Environment Variables In "System Variables", scroll down to select "PATH" ⇒ Edit You cannot undo this so be careful. First copy your existing path to notepad. Then to get the exact PATH to your javac browse manually to the folder where javac resides and click on the address bar and then copy it. It should look something like c:\Program Files\Java\jdk1.8.0_xx\bin In "Variable value" field, paste this IN FRONT of all the existing directories, followed by a semi-colon (;). DO NOT DELETE any existing entries. Variable name : PATH Variable value : c:\Program Files\Java\jdk1.8.0_xx\bin;[Existing Entries...] Now this should resolve. For Linux Based systems try here. Note: The javac command invokes the Java compiler. The compiler will then generate a bytecode file called HelloWorld.class which can be executed in the Java Virtual Machine (JVM). The Java programming language compiler, javac, reads source files written in the Java programming language and compiles them into bytecode class files. Optionally, the compiler can also process annotations found in source and class files using the Pluggable Annotation Processing API. The compiler is a command line tool but can also be invoked using the Java Compiler API. To run your program, enter java followed by the name of the class which contains the main method (HelloWorld in our example). Note how the .class is omitted: $ java HelloWorld Note: The java command runs a Java application. This will output to your console: Hello, World! You have successfully coded and built your very first Java program! Note: In order for Java commands (java, javac, etc) to be recognized, you will need to make sure: A JDK is installed (e.g. Oracle, OpenJDK and other sources) GoalKicker.com – Java® Notes for Professionals 4 Your environment variables are properly set up You will need to use a compiler (javac) and an executor (java) provided by your JVM. To find out which versions you have installed, enter java -version and javac -version on the command line. The version number of your program will be printed in the terminal (e.g. 1.8.0_73). A closer look at the Hello World program The "Hello World" program contains a single file, which consists of a HelloWorld class definition, a main method, and a statement inside the main method. public class HelloWorld { The class keyword begins the class definition for a class named HelloWorld. Every Java application contains at least one class definition (Further information about classes). public static void main(String[] args) { This is an entry point method (defined by its name and signature of public static void main(String[])) from which the JVM can run your program. Every Java program should have one. It is: public: meaning that the method can be called from anywhere mean from outside the program as well. See Visibility for more information on this. static: meaning it exists and can be run by itself (at the class level without creating an object). void: meaning it returns no value. Note: This is unlike C and C++ where a return code such as int is expected (Java's way is System.exit()). This main method accepts: An array (typically called args) of Strings passed as arguments to main function (e.g. from command line arguments). Almost all of this is required for a Java entry point method. Non-required parts: The name args is a variable name, so it can be called anything you want, although it is typically called args. Whether its parameter type is an array (String[] args) or Varargs (String... args) does not matter because arrays can be passed into varargs. Note: A single application may have multiple classes containing an entry point (main) method. The entry point of the application is determined by the class name passed as an argument to the java command. Inside the main method, we see the following statement: System.out.println("Hello, World!"); Let's break down this statement element-by-element: Element Purpose System this denotes that the subsequent expression will call upon the System class, from the java.lang package. GoalKicker.com – Java® Notes for Professionals 5 this is a "dot operator". Dot operators provide you access to a classes members1; i.e. its fields (variables) and its methods. In this case, this dot operator allows you to reference the out static field within the System class. out this is the name of the static field of PrintStream type within the System class containing the standard output functionality. . this is another dot operator. This dot operator provides access to the println method within the out variable. println this is the name of a method within the PrintStream class. This method in particular prints the contents of the parameters into the console and inserts a newline after. ( this parenthesis indicates that a method is being accessed (and not a field) and begins the parameters being passed into the println method. "Hello, World!" this is the String literal that is passed as a parameter, into the println method. The double quotation marks on each end delimit the text as a String. ) this parenthesis signifies the closure of the parameters being passed into the println method. ; this semicolon marks the end of the statement. Note: Each statement in Java must end with a semicolon (;). The method body and class body are then closed. } // end of main function scope } // end of class HelloWorld scope Here's another example demonstrating the OO paradigm. Let's model a football team with one (yes, one!) member. There can be more, but we'll discuss that when we get to arrays. First, let's define our Team class: public class Team { Member member; public Team(Member member) { // who is in this Team? this.member = member; // one 'member' is in this Team! } } Now, let's define our Member class: class Member { private String name; private String type; private int level; // note the data type here private int rank; // note the data type here as well public Member(String name, String type, int level, int rank) { this.name = name; this.type = type; this.level = level; this.rank = rank; } } Why do we use private here? Well, if someone wanted to know your name, they should ask you directly, instead of reaching into your pocket and pulling out your Social Security card. This private does something like that: it prevents outside entities from accessing your variables. You can only return private members through getter functions (shown below).

Free PHP Programming Book

This is just a preview what is inside the PHP reference book if you want the full pdf file feel free to email me at programmingbooks4@gmail.com Chapter 1: Getting started with PHP PHP 7.x Version Supported Until Release Date 7.1 2019-12-01 2016-12-01 7.0 2018-12-03 2015-12-03 PHP 5.x Version Supported Until Release Date 5.6 2018-12-31 2014-08-28 5.5 2016-07-21 2013-06-20 5.4 2015-09-03 2012-03-01 5.3 2014-08-14 2009-06-30 5.2 2011-01-06 2006-11-02 5.1 2006-08-24 2005-11-24 5.0 2005-09-05 2004-07-13 PHP 4.x Version Supported Until Release Date 4.4 2008-08-07 2005-07-11 4.3 2005-03-31 2002-12-27 4.2 2002-09-06 2002-04-22 4.1 2002-03-12 2001-12-10 4.0 2001-06-23 2000-05-22 Legacy Versions Version Supported Until Release Date 3.0 2000-10-20 1998-06-06 2.0 1997-11-01 1.0 1995-06-08 Section 1.1: HTML output from web server PHP can be used to add content to HTML files. While HTML is processed directly by a web browser, PHP scripts are executed by a web server and the resulting HTML is sent to the browser. The following HTML markup contains a PHP statement that will add Hello World! to the output:

When this is saved as a PHP script and executed by a web server, the following HTML will be sent to the user's browser:

Hello world!

PHP 5.x Version ≥ 5.4 echo also has a shortcut syntax, which lets you immediately print a value. Prior to PHP 5.4.0, this short syntax only works with the short_open_tag configuration setting enabled. For example, consider the following code:

Its output is identical to the output of the following:

In real-world applications, all data output by PHP to an HTML page should be properly escaped to prevent XSS (Cross-site scripting) attacks or text corruption. See also: Strings and PSR-1, which describes best practices, including the proper use of short tags (). Section 1.2: Hello, World! The most widely used language construct to print output in PHP is echo: echo "Hello, World!\n"; Alternatively, you can also use print: print "Hello, World!\n"; Both statements perform the same function, with minor differences: echo has a void return, whereas print returns an int with a value of 1 echo can take multiple arguments (without parentheses only), whereas print only takes one argument echo is slightly faster than print Both echo and print are language constructs, not functions. That means they do not require parentheses around their arguments. For cosmetic consistency with functions, parentheses can be included. Extensive examples of the use of echo and print are available elsewhere. C-style printf and related functions are available as well, as in the following example: printf("%s\n", "Hello, World!"); See Outputting the value of a variable for a comprehensive introduction of outputting variables in PHP. Section 1.3: Non-HTML output from web server In some cases, when working with a web server, overriding the web server's default content type may be required. There may be cases where you need to send data as plain text, JSON, or XML, for example. GoalKicker.com – PHP Notes for Professionals 4 The header() function can send a raw HTTP header. You can add the Content-Type header to notify the browser of the content we are sending. Consider the following code, where we set Content-Type as text/plain: header("Content-Type: text/plain"); echo "Hello World"; This will produce a plain text document with the following content: Hello World To produce JSON content, use the application/json content type instead: header("Content-Type: application/json"); // Create a PHP data array. $data = ["response" => "Hello World"]; // json_encode will convert it to a valid JSON string. echo json_encode($data); This will produce a document of type application/json with the following content: {"response":"Hello World"} Note that the header() function must be called before PHP produces any output, or the web server will have already sent headers for the response. So, consider the following code: // Error: We cannot send any output before the headers echo "Hello"; // All headers must be sent before ANY PHP output header("Content-Type: text/plain"); echo "World"; This will produce a warning: Warning: Cannot modify header information - headers already sent by (output started at /dir/example.php:2) in /dir/example.php on line 3 When using header(), its output needs to be the first byte that's sent from the server. For this reason it's important to not have empty lines or spaces in the beginning of the file before the PHP opening tag from files that contain only PHP and from blocks of PHP code at the very end of a file. View the output buffering section to learn how to 'catch' your content into a variable to output later, for example, after outputting headers NOTE. FEEL FREE TO SHARE THE PDF FILE

Free Python Programming Language Book

This is just a preview what's inside Python Book If you want me to send you the complete pdf file just email me at programmingbooks4@gmail.com Language Python 3.x Version Release Date 3.7 2018-06-27 3.6 2016-12-23 3.5 2015-09-13 3.4 2014-03-17 3.3 2012-09-29 3.2 2011-02-20 3.1 2009-06-26 3.0 2008-12-03 Python 2.x Version Release Date 2.7 2010-07-03 2.6 2008-10-02 2.5 2006-09-19 2.4 2004-11-30 2.3 2003-07-29 2.2 2001-12-21 2.1 2001-04-15 2.0 2000-10-16 Section 1.1: Getting Started Python is a widely used high-level programming language for general-purpose programming, created by Guido van Rossum and first released in 1991. Python features a dynamic type system and automatic memory management and supports multiple programming paradigms, including object-oriented, imperative, functional programming, and procedural styles. It has a large and comprehensive standard library. Two major versions of Python are currently in active use: Python 3.x is the current version and is under active development. Python 2.x is the legacy version and will receive only security updates until 2020. No new features will be implemented. Note that many projects still use Python 2, although migrating to Python 3 is getting easier. You can download and install either version of Python here. See Python 3 vs. Python 2 for a comparison between them. In addition, some third-parties offer re-packaged versions of Python that add commonly used libraries and other features to ease setup for common use cases, such as math, data analysis or scientific use. See the list at the official site. Verify if Python is installed To confirm that Python was installed correctly, you can verify that by running the following command in your favorite terminal (If you are using Windows OS, you need to add path of python to the environment variable before using it in command prompt): $ python --version GoalKicker.com – Python® Notes for Professionals 3 Python 3.x Version ≥ 3.0 If you have Python 3 installed, and it is your default version (see Troubleshooting for more details) you should see something like this: $ python --version Python 3.6.0 Python 2.x Version ≤ 2.7 If you have Python 2 installed, and it is your default version (see Troubleshooting for more details) you should see something like this: $ python --version Python 2.7.13 If you have installed Python 3, but $ python --version outputs a Python 2 version, you also have Python 2 installed. This is often the case on MacOS, and many Linux distributions. Use $ python3 instead to explicitly use the Python 3 interpreter. Hello, World in Python using IDLE IDLE is a simple editor for Python, that comes bundled with Python. How to create Hello, World program in IDLE Open IDLE on your system of choice. In older versions of Windows, it can be found at All Programs under the Windows menu. In Windows 8+, search for IDLE or find it in the apps that are present in your system. On Unix-based (including Mac) systems you can open it from the shell by typing $ idle python_file.py. It will open a shell with options along the top. In the shell, there is a prompt of three right angle brackets: >>> Now write the following code in the prompt: >>> print("Hello, World") Hit Enter . >>> print("Hello, World") Hello, World Hello World Python file Create a new file hello.py that contains the following line: Python 3.x Version ≥ 3.0 print('Hello, World') Python 2.x Version ≥ 2.6 You can use the Python 3 print function in Python 2 with the following import statement: from __future__ import print_function Python 2 has a number of functionalities that can be optionally imported from Python 3 using the __future__ module, as discussed here. Python 2.x Version ≤ 2.7 If using Python 2, you may also type the line below. Note that this is not valid in Python 3 and thus not recommended because it reduces cross-version code compatibility. print 'Hello, World' In your terminal, navigate to the directory containing the file hello.py. Type python hello.py, then hit the Enter key. $ python hello.py Hello, World You should see Hello, World printed to the console. You can also substitute hello.py with the path to your file. For example, if you have the file in your home directory and your user is "user" on Linux, you can type python /home/user/hello.py. Launch an interactive Python shell By executing (running) the python command in your terminal, you are presented with an interactive Python shell. This is also known as the Python Interpreter or a REPL (for 'Read Evaluate Print Loop'). $ python Python 2.7.12 (default, Jun 28 2016, 08:46:01) [GCC 6.1.1 20160602] on linux Type "help", "copyright", "credits" or "license" for more information. >>> print 'Hello, World' Hello, World >>> If you want to run Python 3 from your terminal, execute the command python3. $ python3 Python 3.6.0 (default, Jan 13 2017, 00:00:00) [GCC 6.1.1 20160602] on linux Type "help", "copyright", "credits" or "license" for more information. >>> print('Hello, World') Hello, World >>> Alternatively, start the interactive prompt and load file with python -i . In command line, run: $ python -i hello.py "Hello World" >>> There are multiple ways to close the Python shell: >>> exit() or >>> quit() Alternatively, CTRL + D will close the shell and put you back on your terminal's command line. If you want to cancel a command you're in the middle of typing and get back to a clean command prompt, while staying inside the Interpreter shell, use CTRL + C . Try an interactive Python shell online. Other Online Shells Various websites provide online access to Python shells. Online shells may be useful for the following purposes: Run a small code snippet from a machine which lacks python installation(smartphones, tablets etc). Learn or teach basic Python. Solve online judge problems. Examples: Disclaimer: documentation author(s) are not affiliated with any resources listed below. https://www.python.org/shell/ - The online Python shell hosted by the official Python website. https://ideone.com/ - Widely used on the Net to illustrate code snippet behavior. https://repl.it/languages/python3 - Powerful and simple online compiler, IDE and interpreter. Code, compile, and run code in Python. https://www.tutorialspoint.com/execute_python_online.php - Full-featured UNIX shell, and a user-friendly project explorer. http://rextester.com/l/python3_online_compiler - Simple and easy to use IDE which shows execution time Run commands as a string Python can be passed arbitrary code as a string in the shell: $ python -c 'print("Hello, World")' Hello, World This can be useful when concatenating the results of scripts together in the shell. Shells and Beyond Package Management - The PyPA recommended tool for installing Python packages is PIP. To install, on your command line execute pip install . For instance, pip install numpy. (Note: On windows you must add pip to your PATH environment variables. To avoid this, use python -m pip install ) Shells - So far, we have discussed different ways to run code using Python's native interactive shell. Shells use Python's interpretive power for experimenting with code real-time. Alternative shells include IDLE - a pre-bundled NOTE. FEEL FREE TO SHARE THE PDF FILE

Free Visual Basic pdf

This is just a preview of what inside the VISUAL BASIC reference book if you want the full pdf file you can email me at programmingbooks4@gmail.com take a look .NET Language VB.NET Version Visual Studio Version .NET Framework Version Release Date 7.0 2002 1.0 2002-02-13 7.1 2003 1.1 2003-04-24 8.0 2005 2.0 / 3.0 2005-10-18 9.0 2008 3.5 2007-11-19 10.0 2010 4.0 2010-04-12 11.0 2012 4.5 2012-08-15 12.0 2013 4.5.1 / 4.5.2 2013-10-17 14.0 2015 4.6.0 ~ 4.6.2 2015-07-20 15.0 2017 4.7 2017-03-07 Section 1.1: Hello World First, install a version of Microsoft Visual Studio, including the free Community edition. Then, create a Visual Basic Console Application project of type Console Application, and the following code will print the string 'Hello World' to the Console: Module Module1 Sub Main() Console.WriteLine("Hello World") End Sub End Module Then, save and press F5 on the keyboard (or go to the Debug menu, then click Run without Debug or Run) to compile and run the program. 'Hello World' should appear in the console window. Section 1.2: Hello World on a Textbox upon Clicking of a Button Drag 1 textbox and 1 button GoalKicker.com – Visual Basic® .NET Notes for Professionals 3 Double click the button1 and you will be transferred to the Button1_Click event Public Class Form1 Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click End Sub End Class Type the name of the object that you want to target, in our case it is the textbox1. .Text is the property that we want to use if we want to put a text on it. Property Textbox.Text, gets or sets the current text in the TextBox. Now, we have Textbox1.Text We need to set the value of that Textbox1.Text so we will use the = sign. The value that we want to put in the Textbox1.Text is Hello World. Overall, this is the total code for putting a value of Hello World to the Textbox1.Text TextBox1.Text = "Hello World" Adding that code to the clicked event of button1 Public Class Form1 Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click TextBox1.Text = "Hello World" End Sub End Class Section 1.3: Region For the sake of readability, which will be useful for beginners when reading VB code as well for full time developers to maintain the code, we can use "Region" to set a region of the same set of events, functions, or variables: #Region "Events" Protected Sub txtPrice_TextChanged(...) Handles txtPrice.TextChanged 'Do the ops here... End Sub Protected Sub txtTotal_TextChanged(...) Handles txtTotal.TextChanged 'Do the ops here... End Sub 'Some other events.... feel free to share this pdf file

C++ free PDF

This is just a preview of what inside the C++ reference book if you want the full pdf file you can email me at programmingbooks4@gmail.com take a look Chapter 1: Getting started with C++ Version Standard Release Date C++98 ISO/IEC 14882:1998 1998-09-01 C++03 ISO/IEC 14882:2003 2003-10-16 C++11 ISO/IEC 14882:2011 2011-09-01 C++14 ISO/IEC 14882:2014 2014-12-15 C++17 TBD 2017-01-01 C++20 TBD 2020-01-01 Section 1.1: Hello World This program prints Hello World! to the standard output stream: #include int main() { std::cout << "Hello World!" << std::endl; } See it live on Coliru. Analysis Let's examine each part of this code in detail: #include is a preprocessor directive that includes the content of the standard C++ header file iostream. iostream is a standard library header file that contains definitions of the standard input and output streams. These definitions are included in the std namespace, explained below. The standard input/output (I/O) streams provide ways for programs to get input from and output to an external system -- usually the terminal. int main() { ... } defines a new function named main. By convention, the main function is called upon execution of the program. There must be only one main function in a C++ program, and it must always return a number of the int type. Here, the int is what is called the function's return type. The value returned by the main function is an exit code. By convention, a program exit code of 0 or EXIT_SUCCESS is interpreted as success by a system that executes the program. Any other return code is associated with an error. If no return statement is present, the main function (and thus, the program itself) returns 0 by default. In this example, we don't need to explicitly write return 0;. All other functions, except those that return the void type, must explicitly return a value according to their return type, or else must not return at all. THIS BOOK CONTAIN 146 CHAPTER I WASN'T BE ABLE TO SHOW YOU THE FULL BOOK BECAUSE IT WILL EXCEED THE NO. OF TEXT REQUIRED IN POSTING A BLOG About Please feel free to share this PDF with anyone for free,