Lodash - map method

Syntax

_.map(collection, [iteratee=_.identity])

Creates an array of values by running each element in collection thru iteratee. The iteratee is invoked with three arguments: (value, index|key, collection).

Arguments

• collection (Array|Object) − The collection to iterate over.

• [iteratee=_.identity] (Function) − The function invoked per iteration.

Output

• (Array) − Returns the new mapped array.

Example

var _ = require('lodash');
var list = [1, 2, 3, 4];
var users = [
   { 'user': 'Joe' },
   { 'user': 'Robert' }
];
var result = _.map(list, function square(n) {
   return n * n;
});
console.log(result);

result = _.map(users, 'user');
console.log(result);

Save the above program in tester.js. Run the following command to execute this program.

Command

\>node tester.js

Output

[ 1, 4, 9, 16 ]
[ 'Joe', 'Robert' ]