Lodash _.map() Method

Lodash _.map() method creates an array of values by running each element in the collection through the ‘iteratee’. There are many methods that are guarded to work as iteratees for methods like _.every(), _.filter(), _.map(), _.mapValues(), _.reject(), and _.some() methods.

Syntax:

_.map(collection, iteratee)

Parameters:

• collection: This parameter holds the collection to iterate over.
• iteratee: This parameter holds the function invoked per iteration.

Return Value:

This method returns the new mapped array.

Example 1: In this example, we have used the _.map() method on an array and do iteration while using function square.

javascript

// Requiring the lodash library
const _ = require("lodash");

// Original array
let array = _.map([5, 18]);

// Use of _.map() method
let mapped_array =
    _.map(array, function square(n) {
    return n * n;
})

// Printing the output
console.log(mapped_array);

Output:

[ 25, 324 ]

Example 2: In this example, we have used the _.map() method on an object and doing iteration while using function square.

javascript

// Requiring the lodash library
const _ = require("lodash");

// Original array
let array = _.map({ 'x': 14, 'y': 28 });

// Use of _.map() method
let mapped_array =
    _.map(array, function square(n) {
    return n * n;
})

// Printing the output
console.log(mapped_array);

Output:

[ 196, 784 ]