generator.next

generator.next

The next() method returns an object with two properties done and value. You can also provide a parameter to the next method to send a value to the generator.

Syntax

gen.next(value)

Parameters

valueThe value to send to the generator.

Return value

An Object with two properties:

• done (boolean)

Examples

Using next()

The following example shows a simple generator and the object that the next method returns:

function* gen() { 
  yield 1;
  yield 2;
  yield 3;
}

var g = gen( // "Generator { }"
g.next(      // "Object { value: 1, done: false }"
g.next(      // "Object { value: 2, done: false }"
g.next(      // "Object { value: 3, done: false }"
g.next(      // "Object { value: undefined, done: true }"

Sending values to the generator

In this example, next is called with a value. Note that the first call did not log anything, because the generator was not yielding anything initially.

function* gen() {
  while(true) {
    var value = yield null;
    console.log(value
  }
}

var g = gen(
g.next(1 
// "{ value: null, done: false }"
g.next(2 
// "{ value: null, done: false }"
// 2

Specifications

Browser compatibility

See also

• function*

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https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Generator/next