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# How can i determine which part of the array i want to multiply and how do i send it to a new var?

const numbers = [1,2,3,4,5,6,7,8,9,10]; let times10 = [];

// times10 should be: [10,20,30,40,50,60,70,80,90,100] // Write your code below

//Your Code Goes Here: numbers.forEach(function(multiply) { multiply [i] = ""; return times10 = (multiply[i] *= 10); });

I CANNOT FIGURE HOW CAN I TELL THE JS THAT I WANT TO MULTIPLE THE CONST NUMBERS.

app.js
```const numbers = [1,2,3,4,5,6,7,8,9,10];
let times10 = [];

// times10 should be: [10,20,30,40,50,60,70,80,90,100]

numbers.forEach(function(multiply) {
multiply [i] = "";
return times10 = (multiply[i] *= 10);
});
```

With `.forEach()`, you don't need to worry about a counter variable, it's build into the method! So there's no need for an index of `[i]` in your code. I'd also recommend changing your `multiply` parameter to `number`, simply because it will hopefully clarify what is happening in your code - you're iterating over each number in `numbers`.

Right now, you're trying to return the number you've multiplied, but you want to actually add it to the array. You can use the `.push()` method for this.

```numbers.forEach(function(number) {
// multiply the number by 10
// and push it onto the times10 array
});
```

Let me know if you need further clarification!

so it basically knows i want to use all the items inside the array? what if i have a chain of arrays?

Yes, it's basically a shortcut if you want to do something to each item in an array.

```const array = [1, 2, 3, 4];
for (let i=0; i<array.length; i+=1 ) {
console.log(array[i])
}
// output:
// 1
// 2
// 3
// 4

const array = [1, 2, 3, 4];
array.forEach(function(number) {
console.log(number);
});
// output:
// 1
// 2
// 3
// 4
```

The above two loops will produce the same output.

As far as a chain of arrays, can you give me an example of what you mean?

You could use the map-function for this:

```const numbers = [1,2,3,4,5,6,7,8,9,10];
let times10 = [];

// times10 should be: [10,20,30,40,50,60,70,80,90,100]