Lodash _.mapKeys() 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 _.mapKeys() method is used to create an object with the same values as the object and the keys created by running each of the object’s own enumerable string keys.
Syntax:
_.mapKeys( object, iteratee )
Parameters: This method accepts two parameters as mentioned above and described below:
- object: This parameter holds the object to iterate over.
- iteratee: It is the function that is invoked per iteration.
Return Value: This method returns the new mapped object.
Example 1:
Javascript
// Requiring the lodash library const _ = require("lodash"); // Using the _.mapKeys() method console.log( _.mapKeys({ 'cpp': 15, 'java': 40, 'python': 63 }, function(value, key) { return key + value ; } )); |
Output:
{'cpp15': 15, 'java40': 40, 'python63': 63}
Example 2:
Javascript
// Requiring the lodash library const _ = require("lodash"); // The source object var info = { 'GFG': { 'user': 'amit', 'age': 23 }, 'codechef': { 'user': 'priya', 'age': 21 } }; // Using the _.mapKeys() method console.log(_.mapKeys(info, function(o) { return o.age; }) ); |
Output:
{21: {'age': 21, 'user': "priya"}, 23: {'age': 23, 'user': "amit"}}
