Underscore.js _.functionalize() Method

The _.functionalize() method takes a function (one which uses this) and pushes this into the argument list. The returned function uses its first argument as the receiver/context of the original function, and the rest of the arguments are used as the original’s entire argument list.

Syntax:

_.functionalize( function )

Parameters: This method takes a function that uses this.

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:

Javascript

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

function get(g) {
    return this[g];
}

var geekFunc = _.functionalize(get);

var geeks = {
    GeeksforGeeks: "Computer Science Portal for Geeks"
};
console.log(geekFunc(geeks, "GeeksforGeeks"))

Output:

Computer Science Portal for Geeks

Example 2:

Javascript

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

function get(g) {
    return this[g];
}

var geekFunc = _.functionalize(get);

var geeks = {
    GeeksforGeeks: 1000000
};
console.log(geekFunc(geeks, "GeeksforGeeks"))

Output:

1000000