# About this series

This is series of daily JavaScript coding challenges... for both beginners and advanced users.

Each day I’m gone present you a very simple coding challenge, together with the solution. The solution is intentionally written in a didactic way using classic JavaScript syntax in order to be accessible to coders of all levels.

Solutions are designed with increase level of complexity.

## Today’s coding challenge

```
Find the maximum number in a jagged array of numbers or array of numbers
```

(scroll down for solution)

## Code newbies

If you are a code newbie, try to work on the solution on your own. After you finish it, or if you need help, please consult the provided solution.

## Advanced developers

Please provide alternative solutions in the comments below.

You can solve it using functional concepts or solve it using a different algorithm... or just solve it using the latest ES innovations.

By providing a new solution you can show code newbies different ways to solve the same problem.

## Solution

```
// Solution for challenge46a
var ar = [2, 4, 10, [12, 4, [100, 99], 4], [3, 2, 99], 0];
var max = findMax(ar);
println("Max = ", max);
// Use recursion to find the maximum numeric value in an array of arrays
function findMax(ar)
{
var max = -Infinity;
// Cycle through all the elements of the array
for(var i = 0; i < ar.length; i++)
{
var el = ar[i];
// If an element is of type array then invoke the same function
// to find out the maximum element of that subarray
if ( Array.isArray(el) )
{
el = findMax( el );
}
if ( el > max )
{
max = el;
}
}
return max;
}
```

To quickly verify this solution, copy the code above in this coding editor and press "Run".

Note: The solution was originally designed for codeguppy.com environment, and therefore is making use of

`println`

. This is the almost equivalent of`console.log`

in other environments. Please feel free to use your preferred coding playground / environment when implementing your solution.

## Top comments (4)

See I forget

`flat`

is in there. Nice.