# Finding the maximum in a nested array - JavaScript

Let’s say, we have to write a simple function in JavaScript that takes in the following array of Numbers (nested to any level) −

const arr = [
15, 24,
[
29, 85, 56,
[
36, 14, 6, 98, 34, 52
],
22
], 87, 60
];

and return the greatest number present in the array.

For example,

If the input array is −

const arr = [
34, 65, 67,
[
43, 76, 87, 23, 56, 7,
[
54, 7, 87, 23, 79, 994, 2
],
54
], 54, 4, 2
];

Then the output should be −

994

We will use recursion to find the greatest number in the array,

## Example

Following is the code −

const arr = [
34, 65, 67,
[
43, 76, 87, 23, 56, 7,
[
54, 7, 87, 23, 79, 994, 2
],
54
], 54, 4, 2
];
const getGreatest = (arr, greatest = -Infinity) => {
for(let i = 0; i < arr.length; i++){
if(Array.isArray(arr[i])){
return getGreatest(arr[i], greatest);
};
if(arr[i] > greatest){
greatest = arr[i];
}
};
return greatest;
};
console.log(getGreatest(arr));

## Output

This will produce the following output in console −

994