# Populating all values in an array

I was recently tinkering away with JavaScript, when I needed to quickly fill an array with a default value of `0`. At the risk of showing my age and JavaScript naivety, I naturally reached for a `for` loop:

```javascript
const list = [];

for (let i = 0; i < 10; i++) {
    list[i] = 0;
}

// [0: 0, 1: 0, 2: 0, 3: 0, 4: 0, 5: 0, 6: 0, 7: 0, 8: 0, 9: 0]
```

This is fine and will do what I need. However, one of the benefits of JavaScript these days is the syntactic sugar that has been added in more recent releases of ECMAScript. So why not take advantage of `Array.fill()`?

```javascript
const list = Array(10).fill(0);

// [0: 0, 1: 0, 2: 0, 3: 0, 4: 0, 5: 0, 6: 0, 7: 0, 8: 0, 9: 0]
```

The `fill()` method also accepts two further, optional parameters to define the starting and ending indexes. For example, the code below states that we should set the fifth through ninth values of the `list` array with a `0`.

```javascript
const list = Array(10).fill(0, 5, 10);

// [5: 0, 6: 0, 7: 0, 8: 0, 9: 0]
```