Arrays in php, Compare 2 arrays and keep duplicate values

Question

The following are two different definitions of the problem:

How can I process 2 arrays so that I can store data of duplicate [key] values.

I have arrays A and B. I want to create an array C with children so that their id / key values ​​exist in both arrays A and B.

thank

Answer 1

array_intersect_assoc seems to be what you are looking for