The difference between const and define

1. When defining constants using const, only scalar initialization is used, and when you use define to define constants, we can use any form of expression to initialize constants;

2, we can use define in conditional expressions to define constants, but const can not, for example: Defined (' Debug ') or define (' debug ', True)

3, const definition constant large lowercase sensitive; Define defines a constant is a third parameter to determine whether the case is sensitive, the third parameter is set to True, which indicates case sensitivity;

4, starting from PHP5.3, the const can be used outside the class, the previous version can only use const in the class;

The above describes the difference between the const and define, including the contents of the content, I hope that the PHP tutorial interested in a friend helpful.

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