GeneratorFunction() constructor
Baseline
Widely available
This feature is well established and works across many devices and browser versions. It’s been available across browsers since September 2016.
Warning: The arguments passed to this constructor are dynamically parsed and executed 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 passing TrustedScript objects instead of strings and enforcing trusted types.
See Security considerations in the Function() constructor reference for more information.
The GeneratorFunction() constructor creates GeneratorFunction objects.
Note that GeneratorFunction is not a global object. It can be obtained with the following code:
const GeneratorFunction = function* () {}.constructor;
The GeneratorFunction() constructor is not intended to be used directly, and all caveats mentioned in the Function() description apply to GeneratorFunction().
Syntax
new GeneratorFunction(functionBody)
new GeneratorFunction(arg1, functionBody)
new GeneratorFunction(arg1, arg2, functionBody)
new GeneratorFunction(arg1, arg2, /* …, */ argN, functionBody)
GeneratorFunction(functionBody)
GeneratorFunction(arg1, functionBody)
GeneratorFunction(arg1, arg2, functionBody)
GeneratorFunction(arg1, arg2, /* …, */ argN, functionBody)
Note:
GeneratorFunction() can be called with or without new. Both create a new GeneratorFunction instance.
Parameters
See Function().
Examples
Note that these examples omit the use of trusted types for brevity. For code showing the recommended approach, see Using TrustedScript in eval().
Creating and using a GeneratorFunction() constructor
const GeneratorFunction = function* () {}.constructor;
const g = new GeneratorFunction("a", "yield a * 2");
const iterator = g(10);
console.log(iterator.next().value); // 20
Specifications
| Specification |
|---|
| ECMAScript® 2026 Language Specification # sec-generatorfunction-constructor |