is_resource()

is_resource() — Finds whether a variable is a resource.

Built-in function of PHP 8.5. The manual lists it as available in PHP 4, PHP 5, PHP 7, PHP 8. This page is the reference card: signature, parameters and return value, plus the changelog and the example the manual provides.

Signature

is_resource(mixed $value): bool

Parameters

Return value

Returns true if value is a resource, false otherwise.

Example

A runnable snippet:

$handle = fopen("php://stdout", "w"); if (is_resource($handle)) { echo '$handle is a resource'; }

Output:

$handle is a resource

See also

get_resource_type()

All PHP 8.5 built-in functions

Reference card built from the PHP manual page is_resource() (PHP documentation, CC BY 3.0). The page is generated from the manual, so the wording of the parameter and return value text follows php.net.