Underscore.js _.pipeline() Method

The _.pipeline() method takes a list of functions, either as an array or as arguments, and returns a function that takes some value as its argument and runs it through a pipeline of the original functions given in this function.

Syntax:

_.pipeline( func1, func2,..., funcn );

Parameters: This method accepts a single parameter in the form of n functions and hence operate upon given value.

Return Value: This method returns a function.

Note: This will not work in normal JavaScript because it requires the underscore.js contrib library to be installed. 

underscore.js contrib library can be installed using npm install underscore-contrib –save.

Example 1: passing functions as arguments.

Javascript

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

function cb(x) {
    return x * x * x;
};
function tp(x) {
    return 3 * x;
};
function db(x) {
    return 2 * x;
};
let func = _.pipeline(cb, tp, db);

console.log(func(5));

Output:

750

Example 2: Passing functions as an array.

Javascript

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

function cb(x) {
    return x * x * x;
};
function tp(x) {
    return 3 * x;
};
function db(x) {
    return 2 * x;
};

let func = _.pipeline([tp, cb, db]);

console.log(func(5));

Output:

6750