How to return a value from forEach - JavaScript

In this article we will learn how to return a value from forEach in JavaScript.

It is very common to return a value from forEach in JavaScript in JavaScript.

Problem

Now we have a problem which is that we want to return a value from forEach.

But we can't make forEach return a custom value.

// Array
const array = [1, 2, 3, 4, 5];

// Wrong
const newArray = array.forEach(ele => {
    if (ele % 2 != 0) {
        return ele;
    }
    console.log(ele);
});

// `undefined`
console.log(newArray);

Output

undefined

How to solve this problem?

The solution to this problem is very easy. Yes, forEach does not return an output, but it is possible for us to define a variable outside the forEach.

There are other solutions such as using filter or reduce methods.

Return value from forEach using variables

We can define variable outside the forEach and fill it.

Let's see an example

Now we have an array and we want to know what the largest number in that array is, then return that number

// Array
let array = [54, 64, 21, 65, 11, 5];

// Define variable
let result = 0;

// `forEach`
array.forEach(ele => {
    if (ele > result) {
        result = ele;
    }
});

// Result:
console.log(result);

Output

65

Well, what if we want to return more than one number, i.e. filter the array and return more than one element from it.

Let's see an example

Now we want to return numbers greater than 30

// Array
let array = [54, 64, 21, 65, 11, 5];

// Define a variable
let result = [];

// Return numbers more than `30`
array.forEach(ele => {
    if (ele >= 30) {
        result.push(ele);
    }
});

// Result:
console.log(result);

Output

[ 54, 64, 65 ]

Thank you for reading

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