Return the value of the constant indicated by name.
constant is useful if you need to retrieve the value of a constant, but do not know its name. I.e. it is stored in a variable or returned by a function.
This function works also with class constants.
The constant name.
Returns the value of the constant.
Exceptions and Errors
An Error exception is thrown, if the constant is not defined. Prior to PHP 8.0.0, an E_WARNING level error was generated in that case.
|8.0.0||If the constant is not defined, constant now throws an Error exception; previously an E_WARNING was generated, and null was returned.|