[Chapter 21] Reference: Window.setTimeout()
Author: David Flanagan
Date: Fri Aug 29 11:21:35 1997

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| Chapter 21 JavaScript Reference |

# Window.setTimeout() Method

## Name

Window.setTimeout() Method---defer execution of code

## Availability

Navigator 2.0, Internet Explorer 3.0

## Synopsis

    window.setTimeout(code, delay)

### Arguments

`code`

  A string that contains the JavaScript code to be executed after the `delay` has elapsed.

`delay`

  The amount of time, in milliseconds, before the JavaScript statements in the string `code` should be executed.

### Returns

An opaque value (a "timeout id") that can be passed to the `clearTimeout()` method to cancel the execution of `code`.

## Description

The `setTimeout()` method defers the execution of the JavaScript statements in the string `code` for `delay` milliseconds. Once the specified number of milliseconds have elapsed, the statements in `code` are executed normally. Note that they are executed only once. To execute code repeatedly, `code` must itself contain a call to `setTimeout()` to register itself to be executed again.

The statement in the string `code` are executed in the context of `window`--i.e., `window` will be the current window for those statements. If more than one statement appears in `code`, the statements must be separated from each other with semicolons.

## Bugs

In Navigator 2.0 memory allocated by JavaScript is not freed until the browser leaves a web page. Each call to `setTimeout()` consumes some memory, and the deferred code generally consumes memory as well. Thus, if a page performs some sort of infinite loop (for example, a status-bar animation using `Window.setTimeout()` and `Window.status`), then memory will slowly be consumed, and Navigator may crash if the user remains on the page for a long time.

## See Also

"Window", "Window.clearTimeout()"

Window.self |  | Window.status