To find the largest number in an array in JavaScript, do this:

`Math.max(...array)`

.Use the spread operator `...`

to pass all array items into the `Math.max`

function:

```
const array = [ 4, 5, 20, 1, 101, 2 ];
const largestNumber = Math.max(...array);
console.log(largestNumber); // 101
```