array object javascript map code example

Example 1: map object es6

var myObject = { 'a': 1, 'b': 2, 'c': 3 };

Object.keys(myObject).map(function(key, index) {
  myObject[key] *= 2;
});

console.log(myObject);
// => { 'a': 2, 'b': 4, 'c': 6 }

Example 2: javascript map function

/* Answer to: "javascript map function" */

/*
  <Array>.map() - One of the most useful in-built methods in JavaScript (imo).

  The map() method creates a new array populated with the results of calling
  a provided function on every element in the calling array.
 
  For more information, click on the source link.

  Let me make some examples of it's uses:
*/

let array = [1, 4, 9, 16];
array.map(num => num * 2); // [2, 8, 18, 32];
array.map(pounds => `£${pounds}.00`); // ["£1.00", "£4.00", "£9.00", "£16.00"];
array.map(item => Math.sqrt(item)); // [1, 2, 3, 4];

Example 3: functions in map javascript

const map = new Map();

function foo() {
 return "Hello World!"; 
}

map.set("foo", foo);

console.log(map.get("foo")()); // Output: "Hello World!