(PECL runkit7 >= Unknown)
runkit7_constant_add — Similar to define(), but allows defining in class definitions as well
constname
Name of constant to declare. Either a string to indicate a global constant,
or classname::constname to indicate a class constant.
valueNULL, Bool, Long, Double, String, Array, or Resource value to store in the new constant.
newVisibility
Visibility of the constant, for class constants. Public by default.
One of the RUNKIT7_ACC_* constants.
成功时返回 true， 或者在失败时返回 false。