WordPress contains built in functions for quickly returning values.
They are intended to be used as a quick built in function that returns a common value to a filter hook such as true, false, or an empty array.
__return_false
— Returns the Boolean value offalse
.__return_true
— Returns the Boolean value oftrue
.__return_empty_array
— Returns an empty PHParray
.__return_zero
— Returns the integer0
.__return_null
— ReturnsNULL
.__return_empty_string
— Returns''
.