is_callable

Verify that a value can be called as a function from the current scope.

is_callable Function synopsis

is_callable(
    mixed $value,
    bool $syntax_only = false,
    &$callable_name = null
  ): bool

Parameters

$value

Typemixed

The value to be checked.

$syntax_only

OptionalTypeboolDefault valuefalse

If set to true the function only verifies that $value might be a function or method. It will reject any values that are not invokable objects, Closure, strings, or arrays that do not have a valid structure to be used as a callback. A valid callable array has 2 entries, the first of which is an object or a string, and the second a string.

$callable_name

Passed by reference, OptionalDefault valuenull

Receives the "callable name", e.g. "SomeClass::someMethod". Note, however, that despite the implication that SomeClass::someMethod() is a callable static method, this is not the case.

Note that the parameter $callable_name is passed by reference, and contains additional/updated context data that may be useful.

Return value

Typebool

Returns true if $value is callable, false otherwise.