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JavaScript JavaScript Quickstart Arrays and Loops Create a forEach Loop

Posted by Vincent Nguyen
Vincent Nguyen
4,520 Points

How can I store these in the times5 array?

I need help storing the numbers in the times5 array.

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
function multiply(numbers){
  return numbers * 5;
}

3 Answers

Jackson Monk
Jackson Monk
4,527 Points 
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(currentNum) {
  times5.push(currentNum * 5);
});

This way, using forEach, you can iterate through each number and add it to times5

Vincent Nguyen
Vincent Nguyen
4,520 Points

Thank you for helping! :)

Thayer Y
Thayer Y
29,789 Points
Thayer Y
Thayer Y
29,789 Points

it's just another way to pass the challenge. 

numbers.forEach(number => times5.push(number * 5));
Cooper Runstein
Cooper Runstein
11,850 Points
Cooper Runstein
Cooper Runstein
11,850 Points

Jackson is technically right, though forEach is not typically a best practice when working with arrays, it's quite slow when compared to a for loop, and is generally not a good idea if you can avoid it when working with array and array like objects. If you want to use a built in method, map is a better choice when working with arrays. The course you're working on probably wants you to do something like this:

for (let i = 0; i < numbers.length; i++){
    times5.push(numbers[i] * 5)
}

The quickest way to do it in terms of code written is something like:

times5 = numbers.map(num => num*5)

If the second one doesn't make any sense yet, that's fine, in terms of speed and efficiency, the for loop is probably your best bet. If you're comfortable with the second solution, just remember it will only work if you declare times5 with let.

Vincent Nguyen
Vincent Nguyen
4,520 Points

Thank you for helping! :)