Use of the const keyword in the PHP program

: This article mainly introduces the use of the const keyword in the PHP program. if you are interested in the PHP Tutorial, please refer to it. Environment:

In PHP, define can be used to define constants, but define cannot be used in classes. in classes, some attribute values do not want to be modified, in this case, we need to use const to define constants.

Usage:

1. the member attributes modified with const are constants. In a class, const can only modify member attributes.

2. it is recommended to use uppercase letters for constants, but not $

3. the initial value must be given to the constant during the declaration.

4. constant access is the same as static access. use:, but only read

1. use the class name outside the class: constant name

2. use self: constant name inside the class

The above describes the use of the const keyword in the PHP program, including the content, and hope to be helpful to friends who are interested in the PHP Tutorial.