Use of ForEach in Java Script & Node JS - For Each Loop

USE of ForEach in JavaScript 

let friends = ['Vasu', 'Mohit', 'Sunil', 'Abhishek'];

// using forEach

friends.forEach(myFunction);

function myFunction(item) {

    console.log(item)  

}

.

..Output

Vasu

Mohit

Sunil

Abhishek

// For changing in each element  or if you want to something random or same value with each Elecment of array -  Use below code 

let friends = ['Vasu', 'Mohit', 'Sunil', 'Abhishek'];

// using forEach

friends.forEach(myFunction);

function myFunction(item, index, arr) {

 

    arr[index] = 'Hello ' + item;

}

console.log(friends)

..

Output : -

['Hello Vasu', 'Hello Mohit', 'Hello Sunil', 'Hello Abhishek']

FOR vs ForEach both can be used to manipulate Array  

const oldArray = ['item1', 'item2', 'item3'];

const newArray = [];

// using for loop

for (let i = 0; i < oldArray.length; i++) {

  newArray.push(oldArray[i]);

}

console.log(newArray);

// using forEach

oldArray.forEach(function(item){

    newArray.push(item);

  })

  console.log(newArray);

 

....