ContextQMD
Back to Content

WorkerGlobalScope: setInterval() method

files/en-us/web/api/workerglobalscope/setinterval/index.md

latest3.8 KB
Original Source

{{APIRef("HTML DOM")}} {{AvailableInWorkers("window_and_worker")}}

[!WARNING] When the code parameter is used, this method dynamically executes its value as JavaScript. APIs like this are known as injection sinks, and are potentially a vector for cross-site-scripting (XSS) attacks.

You can mitigate this risk by always assigning {{domxref("TrustedScript")}} objects instead of strings and enforcing trusted types. See Security considerations in Window.setInterval() for more information.

The setInterval() method of the {{domxref("WorkerGlobalScope")}} interface repeatedly calls a function or executes a code snippet, with a fixed time delay between each call.

It is commonly used to set a delay for functions that are executed again and again, such as animations. You can cancel the interval using {{domxref("WorkerGlobalScope.clearInterval", "clearInterval()")}}. See {{domxref("Window.setInterval()")}} for more information.

Note that if you wish to have your function called once after the specified delay, use {{domxref("WorkerGlobalScope.setTimeout", "setTimeout()")}}.

Syntax

js-nolint
setInterval(code)
setInterval(code, delay)

setInterval(func)
setInterval(func, delay)
setInterval(func, delay, param1)
setInterval(func, delay, param1, param2)
setInterval(func, delay, param1, param3, /* …, */ paramN)

Parameters

  • func
    • : A {{jsxref("function")}} to be executed every delay milliseconds. The first execution happens after delay milliseconds.
  • code
    • : A {{domxref("TrustedScript")}} or a string of arbitrary code that is compiled and executed every delay milliseconds. This can be used instead of passing a function, but is strongly discouraged for the same reasons that make using {{jsxref("Global_Objects/eval", "eval()")}} a security risk.
  • delay {{optional_inline}}
    • : The delay time between executions of the specified function or code, in milliseconds. Defaults to 0 if not specified. See Delay restrictions in Window.setInterval for details on the permitted range of delay values.
  • param1, …, paramN {{optional_inline}}
    • : Additional arguments which are passed through to the function specified by func once the timer expires.

Return value

A positive integer (typically within the range of 1 to 2,147,483,647) that uniquely identifies the interval timer created by the call.

This identifier, often referred to as an "interval ID", can be passed to {{domxref("WorkerGlobalScope.clearInterval", "clearInterval()")}} to stop the repeated execution of the specified function.

Exceptions

  • {{jsxref("SyntaxError")}}
    • : The code can't be parsed as a script.
  • {{jsxref("TypeError")}}
    • : Thrown if the code parameter is set to a string when Trusted Types are enforced by CSP and no default policy is defined. It is also thrown if the first parameter is not one of the supported types: a function, string or TrustedScript.

Examples

See {{domxref("Window.setInterval", "setInterval()")}} for examples.

Specifications

{{Specifications}}

Browser compatibility

{{Compat}}

See also