I'm not certain if I understand correctly what you think to achieve by using an array. An array is useful if you don't want to deal with a huge amount of variables or you need something that change its size dynamically. Also you can go through all elements of an array very easily. A bad Idea is to change the size of an array every tick by inserting or deleting elements. It will have to reorder the index. Depending of the size of the array it could take some time to do this.
If you store all your Weapons by name or number in an array in the beginning and you want only to cycle through the weapons in the game, you can do this by using the index or use the 'for each element' loop to go through all weapons at once, but I wouldn't use push and pop.