The Intl object is the namespace for the ECMAScript Internationalization API, which provides language sensitive string comparison, number formatting, and date and time formatting. The constructors for Collator, NumberFormat, and DateTimeFormat objects are properties of the Intl object. This page documents these properties as well as functionality common to the internationalization constructors and other language sensitive functions.

Internationalization JavaScript

The deprecated unescape() function computes a new string in which hexadecimal escape sequences are replaced with the character that it represents. The escape sequences might be introduced by a function like escape. Because unescape is deprecated, use decodeURI or decodeURIComponent instead.

Deprecated JavaScript

This chapter documents all the JavaScript language operators, expressions and keywords.

JavaScript Operators

The break statement terminates the current loop, switch, or label statement and transfers program control to the statement following the terminated statement.

JavaScript Statement

The continue statement terminates execution of the statements in the current iteration of the current or labeled loop, and continues execution of the loop with the next iteration.

JavaScript Statement

The debugger statement invokes any available debugging functionality, such as setting a breakpoint. If no debugging functionality is available, this statement has no effect.

JavaScript Statement

The default keyword can be used in two situations in JavaScript: within a switch statement, or with an export statement.

JavaScript Keyword

The do...while statement creates a loop that executes a specified statement until the test condition evaluates to false. The condition is evaluated after executing the statement, resulting in the specified statement executing at least once.

JavaScript Statement

An empty statement is used to provide no statement, although the JavaScript syntax would expect one.

JavaScript Statement

The for...in statement iterates over the enumerable properties of an object, in arbitrary order. For each distinct property, statements can be executed.

JavaScript Statement

The function declaration defines a function with the specified parameters.

JavaScript Statement

The if statement executes a statement if a specified condition is true. If the condition is false, another statement can be executed.

JavaScript Statement

The labeled statement can be used with break or continue statements. It is prefixing a statement with an identifier which you can refer to.

JavaScript Statement

The return statement ends function execution and specifies a value to be returned to the function caller.

JavaScript Statement

The throw statement throws a user-defined exception. Execution of the current function will stop (the statements after throw won't be executed), and control will be passed to the first catch block in the call stack. If no catch block exists among caller functions, the program will terminate.

JavaScript Statement

The try...catch statement marks a block of statements to try, and specifies a response, should an exception be thrown.

JavaScript Statement

The variable statement declares a variable, optionally initializing it to a value.

JavaScript Statement

The while statement creates a loop that executes a specified statement as long as the test condition evaluates to true. The condition is evaluated before executing the statement.

JavaScript Statement

ECMAScript 5 introduced strict mode which is now implemented in all major browsers (including IE10). While making web browsers interpret code as strict is easy (just add "use strict"; at the top of your source code), transitioning an existing code base to strict mode requires a bit more work.

Advanced JavaScript

The experimental JavaScript SIMD API introduces vector objects that utilize SIMD/SSE instructions on supporting CPUs; SIMD is short for Single Instruction/Multiple Data. SIMD operations are methods that process multiple data with a single instruction. In contrary, scalar operations (SISD) process only one individual data with a single instruction.

JavaScript SIMD