Underscore.js _.iterators.accumulate() method

With the help of _.iterators.accumulate(iter, binaryFn) method, we can get the new iterator function which when called will iterate the next step with iter and generate the value by using binaryFn.

Syntax: 

_.iterators.accumulate(iter, binaryFn)

Return: Return the iterator function which will generally result in an accumulated Binary function.

Example 1: In this example, we can see that by using _.iterators.accumulate(iter, binaryFn) method, we are able to get the function iterator which will return the value by using the accumulated binary function.

// Defining underscore contrib variable
const _ = require('underscore-contrib');

let iter = _.iterators.List(["Geeks", "for", "Geeks"]);

function calculateLength(geeky, element) {
    return element.length;
}

let gfg = _.iterators.accumulate(iter, calculateLength, 0);

for (let i = 0; i < 3; i++) {
    console.log(gfg());
}

Output:

5
3
5

Example 2: In this example, we will see the use of  _.iterators.accumulate(iter, binaryFn) method.

// Defining underscore contrib variable
const _ = require('underscore-contrib');

let iter = _.iterators.List(["A", "AB", "ABC", "AB", "A"]);

function calculateLength(geeky, element) {
    return element.length;
}

let gfg = _.iterators.accumulate(iter, calculateLength, 0);

for (let i = 0; i < 5; i++) {
    console.log(gfg());
}

Output:

1
2
3
2
1