Javascript variable initialization

Question

There, an odd thing just happened..

Normally I assign my global variables like this:

orders = [];
pOrders = [];

But I was lazy and just wrote:

orders = pOrders = [];

It should mean the same, shouldn't it??

Apparently not because the array pOrder also contained the array orders data. I sat for 15 min looking for a bug in my code but couldn't find any so I just tried writing the variables as I normally would and it worked. Why does this happen?

In PHP, the logic would be the same, but JavaScript seems to behave differently.

Please could anyone provide me with some information, or knowledge..

Answer 1

In the second example, you're explicitly assigning the exact same array instance to two separate variables. There's only one array involved, while in the first case there are two.

I would be somewhat surprised to learn that PHP really would treat those two pieces of code as meaning the same thing.