Missing from the array

PHP
1

Hi

I have a array like this
(1-1,1-2,1-4,2-2,2-4)

And I want to retrieve the missing

For example, I want to retrieve from the previous array (1-3,2-1,2-3)

Thanks

2

Is this a homework assignment? :wink:

Regardless, have a go at it, post your code and we’ll help you to the solution. We’re not here to write code for people…