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Exponentiation makes the second operand the power of the first operand (ab). var a = 2, b = 3, c = Math.pow(a, b); c will now be 8 6 Stage 3 ES2016 (ECMAScript 7) Proposal: let a = 2, b = 3, c = a ** b; c will now be 8 Use Math.pow to find the nth root of a number....

print_r() - Outputting Arrays and Objects for debugging print_r will output a human readable format of an array or object. You may have a variable that is an array or object. Trying to output it with an echo will throw the error: Notice: Array to string conversion. You can instead use the print_r...

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 retu...

This program prints Hello World! to the standard output stream: #include <iostream> 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 <iostream> is a...

var x = true, y = false; AND This operator will return true if both of the expressions evaluate to true. This boolean operator will employ short-circuiting and will not evaluate y if x evaluates to false. x && y; This will return false, because y is false. OR This operator wil...

To create a simple C program which prints "Hello, World" on the screen, use a text editor to create a new file (e.g. hello.c — the file extension must be .c) containing the following source code: hello.c #include <stdio.h> int main(void) { puts("Hello, World")...

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 (in...

Place this code in a file named HelloWorld.scala: object Hello { def main(args: Array[String]): Unit = { println("Hello World!") } } Live demo To compile it to bytecode that is executable by the JVM: $ scalac HelloWorld.scala To run it: $ scala Hello When the Scala...

Introduction HTML (Hypertext Markup Language) uses a markup system composed of elements which represent specific content. Markup means that with HTML you declare what is presented to a viewer, not how it is presented. Visual representations are defined by Cascading Style Sheets (CSS) and realized...

Consider a database with the following two tables. Employees table: IdFNameLNameDeptId1JamesSmith32JohnJohnson4 Departments table: IdName1Sales2Marketing3Finance4IT Simple select statement * is the wildcard character used to select all available columns in a table. When used as a substitute f...

The JSONSerialization class is built into Apple's Foundation framework. 2.2 Read JSON The JSONObjectWithData function takes NSData, and returns AnyObject. You can use as? to convert the result to your expected type. do { guard let jsonData = "[\"Hello\", \"JSON\"]&q...

Enum cases can contain one or more payloads (associated values): enum Action { case jump case kick case move(distance: Float) // The "move" case has an associated distance } The payload must be provided when instantiating the enum value: performAction(.jump) performA...

Enums without payloads can have raw values of any literal type: enum Rotation: Int { case up = 0 case left = 90 case upsideDown = 180 case right = 270 } Enums without any specific type do not expose the rawValue property enum Rotation { case up case right cas...

Logical OR (||), reading left to right, will evaluate to the first truthy value. If no truthy value is found, the last value is returned. var a = 'hello' || ''; // a = 'hello' var b = '' || []; // b = [] var c = '' || undefined; // c = undefined var d = 1 |...

Standard While Loop A standard while loop will execute until the condition given is false: var i = 0; while (i < 100) { console.log(i); i++; } Expected output: 0 1 ... 99 Decremented loop var i = 100; while (i > 0) { console.log(i); i--; /* equivalent to i...

Place the following code into a file name hello.go: package main import "fmt" func main() { fmt.Println("Hello, 世界") } Playground When Go is installed correctly this program can be compiled and run like this: go run hello.go Output: Hello, 世界 Once you are...

A decorator takes just one argument: the function to be decorated. There is no way to pass other arguments. But additional arguments are often desired. The trick is then to make a function which takes arbitrary arguments and returns a decorator. Decorator functions def decoratorfactory(message): ...

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: Step by Step explanation: require "tk" Load the tk package...

Open a new blank document in the MATLAB Editor (in recent versions of MATLAB, do this by selecting the Home tab of the toolstrip, and clicking on New Script). The default keyboard shortcut to create a new script is Ctrl-n. Alternatively, typing edit myscriptname.m will open the file myscriptname.m ...

Match Using .exec() RegExp.prototype.exec(string) returns an array of captures, or null if there was no match. var re = /([0-9]+)[a-z]+/; var match = re.exec("foo123bar"); match.index is 3, the (zero-based) location of the match. match[0] is the full match string. match[1] is the t...