I can't get the value of the variable

Question

I'm learning JavaScript and there is a question that I can't understand:

Consider the given code:

let names = ['ahmed', 'karima', 'hamza','soad'];  
let modifiedNames = names.forEach(name => name+99);

The value of modifiedNames here will be?

I am printing the variable in the console but it gives me undefined?!

Thank you in advance.

Answer 1

You use Array.prototype.forEach which always returns undefined. Use Array.prototype.map if you want to map your array into a new one.

let names = ['ahmed', 'karima', 'hamza','soad'];  
let modifiedNames = names.map(name => name+99);
console.log(modifiedNames);

Answer 2

Look at the documentation for forEach:

Return value

undefined.

Therefore modifiedNames will be undefined.