function* expression

The function* keyword can be used to define a generator function inside an expression.

Syntax

function* [name]([param1[, param2[, ..., paramN]]]) {
   statements
}

Parameters

name
The function name. Can be omitted, in which case the function is anonymous. The name is only local to the function body.
paramN
The name of an argument to be passed to the function. A function can have up to 255 arguments.
statements
The statements which comprise the body of the function.

Description

A function* expression is very similar to and has almost the same syntax as a function* statement. The main difference between a function* expression and a function* statement is the function name, which can be omitted in function* expressions to create anonymous generator functions. See also the chapter about functions for more information.

Examples

The following example defines an unnamed generator function and assigns it to x. The function yields the square of its argument:

var x = function*(y) {
   yield y * y;
};

Specifications

Specification Status Comment
ECMAScript 2015 (6th Edition, ECMA-262)
The definition of 'function*' in that specification.
Standard Initial definition.
ECMAScript Latest Draft (ECMA-262)
The definition of 'function*' in that specification.
Draft  

Browser compatibility

Update compatibility data on GitHub
DesktopMobileServer
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidFirefox for AndroidOpera for AndroidSafari on iOSSamsung InternetNode.js
function*Chrome Full support 49Edge Full support 12Firefox Full support 26IE No support NoOpera Full support 36Safari Full support 10WebView Android Full support 49Chrome Android Full support 49Firefox Android Full support 26Opera Android Full support 36Safari iOS Full support 10Samsung Internet Android Full support 5.0nodejs Full support Yes
Trailing comma in parametersChrome Full support 58Edge No support NoFirefox Full support 52IE No support NoOpera Full support 45Safari ? WebView Android Full support 58Chrome Android Full support 58Firefox Android Full support 52Opera Android Full support 43Safari iOS ? Samsung Internet Android Full support 7.0nodejs Full support 8.0.0

Legend

Full support  
Full support
No support  
No support
Compatibility unknown  
Compatibility unknown

See also