Underscore.js _.ternary() Method

The Underscore.js _.ternary() method returns a new function that accepts only three arguments and passes these arguments to the given function. Any additional arguments that are given are discarded.

Syntax:

_.ternary( fun )

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

• fun: This is the function that should be used for the parameters.

Return Value: This method returns a new function.

Note: This method will not work in normal JavaScript because it requires the underscore-contrib library to be installed. It can be installed using npm install underscore-contrib

Example 1:

Javascript

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

// Function to be used
function fun() {
    return arguments;
}

// Making ternary function
var gfgFunc = _.ternary(fun);

console.log("Arguments are :",
    gfgFunc(1, 2, 3));

Output:

Arguments are : [Arguments] { '0': 1, '1': 2, '2': 3 }

Example 2:

Javascript

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

// Function to be used
function fun() {
    return arguments;
}

// Making the ternary function
var gfgFunc = _.ternary(fun);

// Arguments more than 3 are excluded
console.log("Arguments are :",
    gfgFunc(1, 2, 3, 4, 5, 6, 7, 8));

Output: 

Arguments are : [Arguments] { '0': 1, '1': 2, '2': 3 }

Example 3: In this example, we will add arguments but only the first 3 arguments will be using this method.

Javascript

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

// Function to be used
function add() {
    s=0;
    for (i=0; i<3; i++) {
        s+=arguments[i];
    }
    return s;
}

// Making the ternary function
var gfgFunc = _.ternary(add);

// Arguments more than 3 are excluded
console.log("Sum of first 3 arguments is :",
    gfgFunc(1, 2, 3, 4, 5, 6, 7));

Output: 

Sum of first 3 arguments is : 6