Core JavaScript 1.5 Reference:Statements

From MDC

This section describes all JavaScript statements. JavaScript statements consist of keywords used with the appropriate syntax. A single statement may span multiple lines. Multiple statements may occur on a single line if each statement is separated by a semicolon.

Syntax conventions: All keywords in syntax statements are non-italicized. Words in italics represent user-defined names or statements. Any portions enclosed in square brackets ("[" and "]") are optional. A comma-delimited sequence that includes an ellipsis ("...") indicates that the sequence is a list and all items in the sequence except the first are optional (e.g. only param1 is required in "param1, param2, ..., paramN").

block

A block statement is used to group zero or more statements. The block is delimited by a pair of curly brackets.

break

Terminates the current loop, switch, or labelled statement and transfers program control to the statement following the terminated statement.

const

Declares a global constant and initializes it to a value.

continue

Terminates execution of the statements in the current iteration of the current or labelled loop, and continues execution of the loop with the next iteration.

do...while

Creates a loop that executes a specified statement until the test condition evaluates to false. The statement is always executed at least once.

export

Allows a signed script to provide properties, functions, and object to other signed or unsigned scripts.

for

Creates a loop that consists of three optional expressions, enclosed in parentheses and separated by semicolons, followed by a statement executed in the loop.

for...in

Iterates a specified variable over all the properties of an object. For each distinct property, a specified statement is executed.

for each...in

Iterates a specified variable over all values of object's properties. For each distinct property, a specified statement is executed.

function

Declares a function.

if...else

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

import

Allows a script to import properties, functions, and objects from a signed script that has exported the information.

label

Provides an identifier that can be used with break or continue to indicate where the program should continue execution.

let

Temporarily assigns a value to a variable that only effects the current local scope.

return

Specifies the value to be returned by a function.

switch

Evaluates an expression, matching the expression's value to a case label, and executes statements associated with that case.

throw

Throws a user-defined exception.

try...catch

Marks a block of statements to try, and specifies a response, should an exception be thrown.

var

Declares a variable, optionally initializing it to a value.

while

Creates a loop that executes a specified statement as long as the test condition evaluates to true. The statement is executed after evaluating the condition.

with

Extends the scope chain for a statement.