javascript map index code example

Example 1: es6 map usin index

const array = [1, 2, 3, 4];


const map = array.map((x, index) => {
  console.log(index);
  return x + index;
});

console.log(map);

Example 2: 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 3: map javascript index

// Arrow function
map((element) => { ... } )
map((element, index) => { ... } )
map((element, index, array) => { ... } )

// Callback function
map(callbackFn)
map(callbackFn, thisArg)

// Inline callback function
map(function callbackFn(element) { ... })
map(function callbackFn(element, index) { ... })
map(function callbackFn(element, index, array){ ... })
map(function callbackFn(element, index, array) { ... }, thisArg)

Example 4: map index

array.map((currentelement, index) => {
	
});

Example 5: 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 6: array map

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]