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JavaScript JavaScript Quickstart Arrays and Loops Create a forEach Loop

Posted by Chris Roper
Chris Roper
6,934 Points

JavaScript Quickstart create a forEach loop

Using forEach, iterate over the numbers array and multiply each number by 5, storing these new numbers in the times5 array.

times5 should be: [5,10,15,20,25,30,35,40,45,50] Write your code below

My first answer: times5 = numbers.forEach(num => console.log(num * 5));

It ran in my text editor but not in the code challenge. It just logged 50 to the console not 5 to 50?

Second attempt: numbers.forEach(num => times5 = num * 5);

console.log(times5);

It logged 5 to 50 to the console but I have a feeling it didn't assign them to the times5 variable properly but why?

app.js 
const numbers = [1,2,3,4,5,6,7,8,9,10];
let times5 = [];

// times5 should be: [5,10,15,20,25,30,35,40,45,50]
// Write your code below

1 Answer

Alexander Besse
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.a{fill-rule:evenodd;}techdegree seal-36
Alexander Besse
Full Stack JavaScript Techdegree Graduate 35,115 Points
Alexander Besse
.a{fill-rule:evenodd;}techdegree seal-36
Alexander Besse
Full Stack JavaScript Techdegree Graduate 35,115 Points

Hi Chris Roper!

I want to clarify some logic in your first and second attempts at the coding challenge. The objective of the task is to loop over all the numbers in the numbers array and then store the given number * 5 in the times5 array.

My first answer: times5 = numbers.forEach(num => console.log(num * 5));

The .forEach() array method doesn't return anything. The code attempt below will run the .forEach() loop but then set times5 to null when it's done.

Second attempt: numbers.forEach(num => times5 = num * 5);

This is much closer. You're looping over each element in the numbers array, good! But, you're setting times5 to the value of num * 5. Remember, we want to append the value of num * 5 to the times5 array - not set times5 to an integer value.

Your code should look like this:

numbers.forEach(num => times5.push(num * 5));

Hopefully, that helps. Happy coding!

Chris Roper
Chris Roper
6,934 Points

Great thanks! That makes much more sense now.