JavaScript Generator next() Method
Last Updated :
23 May, 2023
JavaScript Generator.prototype.next() method is an inbuilt method in JavaScript that is used to return an object with two properties done and value.
Syntax:
gen.next( value );
Parameters: This function accepts a single parameter as mentioned above and described below:
- value: This parameter holds the value to be sent to the generator.
Return value: This method returns an object containing two properties:
- done: It has the value
- true - for the iterator which is past the end of the iterated sequence.
- false - for the iterator which is able to produce the next value in the sequence.
- value: It contains any JavaScript value which is returned by the iterator.
The below examples illustrate the Generator.prototype.next() method in JavaScript:
Example 1: In this example, we will create a generator and then apply the Generator.prototype.next() method and see the output.
javascript
function* GFG() {
yield "GeeksforGeeks";
yield "JavaScript";
yield "Generator.prototype.next()";
}
const geek = GFG();
console.log(geek.next());
console.log(geek.next());
console.log(geek.next());
console.log(geek.next());
Output:
Object { value: "GeeksforGeeks", done: false }
Object { value: "JavaScript", done: false }
Object { value: "Generator.prototype.next()", done: false }
Object { value: undefined, done: true }
Example 2: In this example, we will create a generator and then apply the Generator.prototype.next() method and see the output.
javascript
function* GFG(len, list) {
let result = [];
let val = 0;
while (val < list.length) {
result = [];
let i = val
while (i < val + len) {
if (list[i]) {
result.push(list[i]);
}
i += 1
}
yield result;
val += len;
}
}
list = [
'geeks1', 'geeks2', 'geeks3',
'geeks4', 'geeks5', 'geeks6',
'geeks7', 'geeks8', 'geeks9',
'geeks10', 'geeks11'
];
let geek = GFG(4, list);
console.log(geek.next().value);
console.log(geek.next().value);
console.log(geek.next().value);
console.log(geek.next().value);
Output:
geeks1,geeks2,geeks3,geeks4
geeks5,geeks6,geeks7,geeks8
geeks9,geeks10,geeks11
undefined
Supported Browsers: The browsers supported by Generator.prototype.next() method are listed below:
- Google Chrome
- Firefox
- Opera
- Safari
- Edge
We have a complete list of Javascript Generator methods, to check those please go through the Javascript Generator Reference article.