map javascirpt code 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: javascript map

array.map((item) => {
  return item * 2
} // an example that will map through a a list of items and return a new array with the item multiplied by 2

Example 3: initialize a map js

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

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

Example 4: javascript map array

const sweetArray = [2, 3, 4, 5, 35]
const sweeterArray = sweetArray.map(sweetItem => {
    return sweetItem * 2
})

console.log(sweeterArray)

Example 5: map in javascript

let myMap = new Map()

let keyString = 'a string'
let keyObj    = {}
// setting the values
myMap.set(keyString, "value associated with 'a string'")
myMap.set(keyObj, 'value associated with keyObj')
myMap.set(keyFunc, 'value associated with keyFunc')
myMap.size              // 3
// getting the values
myMap.get(keyString)    // "value associated with 'a string'"
myMap.get(keyObj)       // "value associated with keyObj"
myMap.get(keyFunc)      // "value associated with keyFunc"

Example 6: javascript map

The map() method creates a new array with the results of calling a provided function on every element in the calling array.