define Defines a named constant &reftitle.description; booldefine stringname mixedvalue boolcase_insensitivefalse Defines a named constant at runtime. &reftitle.parameters; name The name of the constant. value The value of the constant. In PHP 5, value must be a scalar value (integer, float, string, boolean, or &null;). In PHP 7, array values are also accepted. While it is possible to define resource constants, it is not recommended and may cause unpredictable behavior. case_insensitive If set to &true;, the constant will be defined case-insensitive. The default behavior is case-sensitive; i.e. CONSTANT and Constant represent different values. Case-insensitive constants are stored as lower-case. &reftitle.returnvalues; &return.success; &reftitle.changelog; &Version; &Description; 7.0.0 array values are allowed. &reftitle.examples; ]]> &reftitle.seealso; defined constant The section on Constants