问题
Is there a way to declare a variable so it is available in all functions. Basically I want to call: Global $varName; automatically for every function. And no, I can't use a constant.
I don't think its possible but wanted to ask anyway. Thanks! :D
回答1:
That's pretty oldschool and not recommended. If you want to use variables whereever you want consider using sessions of passing through variables if you're on an object oriented tour ;)
回答2:
There is a $GLOBALS variable and a globals keyword.Check out example 1 and 2 on this page in the documentation.
But using a global variable is usually a sign of bad structure in your code.
回答3:
I don't think variables can be globally visible the way you want bnut functions are.
You can declare two functions to access you data : on for reading, one for writing.
But anyway beware : if you change it from many places you will have hard times understanding what's going on when faced with a bug !
来源：https://stackoverflow.com/questions/1781780/php-variable-scope