array map js example

Example 1: javascript map array

const myArray = ['Sam', 'Alice', 'Nick', 'Matt'];

// Appends text to each element of the array
const newArray = myArray.map(name => {
	return 'My name is ' + name; 
});
console.log(newArray); // ['My name is Sam', 'My Name is Alice', ...]

// Appends the index of each element with it's value
const anotherArray = myArray.map((value, index) => index + ": " + value);
console.log(anotherArray); // ['0: Sam', '1: Alice', '2: Nick', ...]

// Starting array is unchanged
console.log(myArray); // ['Sam', 'Alice', 'Nick', 'Matt']

Example 2: array map javascript

const array1 = [1, 4, 9, 16];

// pass a function to map
const map1 = array1.map(x => x * 2);

console.log(map1);
// expected output: Array [2, 8, 18, 32]

Example 3: javascript map

const numbers = [0,1,2,3];

console.log(numbers.map((number) => {
  return number;
}));

Example 4: nodejs map

let wrongMap = new Map()
wrongMap['bla'] = 'blaa'
wrongMap['bla2'] = 'blaaa2'

console.log(wrongMap)  // Map { bla: 'blaa', bla2: 'blaaa2' }