如何组合两个不同的阵列并根据出现的次数对它们进行适当的排序？

I have some simple php code that allows me to find the top number of registered users from a the most active zip codes and by extension, the most active state. However I want to find the most active counties. The problem is that the same county name are used in multiple states, so you don't want to add them together.I have some simple php code that allows me to f