I am currently working on a project that involves comparing two arrays and finding the differences based on their keys. I came across the `array_diff_key()` function in PHP which seems to do exactly that, but I am having trouble understanding how it works and how to use it properly.
I have two arrays, let's call them `$array1` and `$array2`. Both arrays have several key-value pairs, and I want to find the keys that are present in `$array1` but not in `$array2`. As far as I understand, the `array_diff_key()` function should help me achieve this.
However, I am struggling with grasping the concept of this function and how to use it properly in my code. I would really appreciate it if someone could provide a clear explanation of how the `array_diff_key()` function works and provide an example or two to help me understand it better.
Thank you in advance for your help!