How To Iterate an Array using forEach Loop in JavaScript?

Iterating through an array in JavaScript can be done in multiple ways. One of the most common methods is using the traditional for loop.

The modern approach to iterate the array which is by using the forEach method. This method is different from the traditional approach as it uses a functional approach. It provides us with new ways to access each element of the array as well as the whole array. Since we use a functional approach therefore we can also use arrow function syntax with this method.

Syntax:

arr.forEach(function(val, index, wholeArr)){
    . . .
}

let arr = [2, 4, 7, 8, 1]

arr.forEach(function(val){
    console.log(val)
})

2
4
7
8
1

Example 2: Iterating through an array using the arrow function.

let arr = [2, 4, 7, 8, 1]

arr.forEach((val, index) => {console.log(`val=${val} index=${index} `)})

val=2 index=0 
val=4 index=1 
val=7 index=2 
val=8 index=3 
val=1 index=4 

Example 3: Accessing the whole array with the third optional parameter.

let arr = [2, 4, 7, 8]

arr.forEach((val, index, wholeArr) => {console.log(wholeArr)})

[ 2, 4, 7, 8 ]
[ 2, 4, 7, 8 ]
[ 2, 4, 7, 8 ]
[ 2, 4, 7, 8 ]