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JavaScript JavaScript Quickstart Arrays and Loops Create a forEach Loop

Posted by Unsubscribed User
.a{fill-rule:evenodd;}techdegree
Unsubscribed User
Front End Web Development Techdegree Student 33,900 Points

Looking for help with forEach loop - code challenge

I am looking for a hint to solve the code challenge creating a forEach loop.

The task says:

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

My current code is:

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

numbers.forEach(function(number) {
  times5[number] = number * 5;
});

I get the error message:

"Bummer: Something's not right. Output of times5: [null,5,10,15,20,25,30,35,40,45,50]"

And I don't really get it why the first value in the created array is null.

Anyone can give me a hint?

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

numbers.forEach(function(number) {
  times5[number] = number * 5;
});

2 Answers

Cheo R
Cheo R
37,150 Points
Cheo R
Cheo R
37,150 Points

It's because you're not inserting the results at index 0 in the times5 array.

numbers.forEach(function(number) {
  times5[number] = number * 5;
});

Say number is 1.

1 * 5 is 5.

times5[1] has the value 5. The rest get inserted sequential. Arrays are zero-based.

Currently there's nothing at index 0. You get null.

Unsubscribed User
.a{fill-rule:evenodd;}techdegree
Unsubscribed User
Front End Web Development Techdegree Student 33,900 Points

Thanks a lot. I got it right now. :-)

Noah Ellekjær
Noah Ellekjær
2,739 Points
Noah Ellekjær
Noah Ellekjær
2,739 Points

I Still can't get it right, would you mind sharing the correct answer?