Lodash _.ternary() Method

Lodash is a JavaScript library that works on the top of underscore.js. Lodash helps in working with arrays, strings, objects, numbers, etc.

The _.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 takes a single parameter as listed above and discussed 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 Lodash contrib library to be installed. The lodash-contrib library can be installed using npm install lodash-contrib –save

Example 1:

Javascript

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

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

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

console.log("Arguments are :",
    gfgFunc("first", "second", "third"));

Output:

Arguments are : [Arguments] 
  { '0': 'first', '1': 'second', '2': 'third' }

Example 2:

Javascript

// Defining lodash contrib variable
var _ = require('lodash-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("a", "b", "c", "d", "e", "f"));

Output: 

Arguments are : [Arguments] { '0': 'a', '1': 'b', '2': 'c' }

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

Javascript

// Defining lodash contrib variable
var _ = require('lodash-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(100, 100, 1000, 4, 5, 6, 7));

Output: 

Sum of first 3 arguments is : 1200