JavaScript Generator return() Method

JavaScript Generator.prototype.return() method is an inbuilt method in JavaScript that is used to return the given value and finishes the generator.

Syntax:

gen.return( value );

Parameters: This method accepts a single parameter as mentioned above and described below: 

• value: This parameter holds the value to be returned.

Return value: This method returns the value which is given to it as an argument.

The below examples illustrate the Generator.prototype.return() method in JavaScript:

Example 1: This example shows the use of the Generator.prototype.return() method in JavaScript.

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.return("Shubham  Singh"));
console.log(geek.next());

Output:

Object { value: "GeeksforGeeks", done: false }
Object { value: "JavaScript", done: false }
Object { value: "Shubham  Singh", done: true }
Object { value: undefined, done: true }

Example 2: In this example, we will create a generator function and then apply the Generator.prototype.return() method and see the result.

javascript

function* GFG(pageSize = 1, list) {
    let output = [];
    let index = 0;

    while (index < list.length) {
        output = [];
        for (let i = index; i < index + pageSize; i++) {
            if (list[i]) {
                output.push(list[i]);
            }
        }

        yield output;
        index += pageSize;
    }
}
list = [1, 2, 3, 4, 5, 6, 7, 8]
let geek = GFG(3, list);

console.log(geek.next());
console.log(geek.next());
console.log(geek.next());
console.log(geek.next());
console.log(geek.return(list));

Output:

Object { value: Array [1, 2, 3], done: false }
Object { value: Array [4, 5, 6], done: false }
Object { value: Array [7, 8], done: false }
Object { value: undefined, done: true }
Object { value: Array [1, 2, 3, 4, 5, 6, 7, 8], done: true }

Supported Browsers: The browsers supported by Generator.prototype.return() method are listed below: 

• Google Chrome 50 and above
• Edge 13 and above
• Firefox 38 and above
• Opera 37 and above
• safari 10 and above

We have a complete list of Javascript Generator methods, to check those please go through the Javascript Generator Reference article.