index in map javascript code example

Example 1: 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 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 array

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

console.log(sweeterArray)

Example 4: array mdn map

let new_array = arr.map(function callback( currentValue[, index[, array]]) {
    // return element for new_array
}[, thisArg])