Type System

Type declarations can be added to function arguments, return values, and, as of PHP 7.4.0, class properties. They ensure that the value is of the specified type at call time, otherwise a TypeError is thrown.

<?php

    function trumpet(Elephpant $trunk) : void {}

    class Herd {
        private Elephpant $tusk;
    }

?>

Documentation

See Also

• Explore Your Types
• Narrowing types for static analysis
• PHP Oddities
• Types

Related

• Disjunctive Normal Form (DNF)
• False
• Mixed
• Never Type
• Nullable
• Object
• Properties
• Return Type
• strict_types
• True
• Property Type Declaration
• Typed Property
• Intersection Type
• Object Type
• Scalar Types
• Special Types
• Union Type
• Variables
• Autowiring
• Propagation
• Pseudo-type
• Type Coverage
• Dependent Type
• Gradual Type Checking
• Relative Types
• Standalone Types
• Autocompletion
• Question Mark ?
• resource
• Types Erasure
• Type Inference
• Alias Types
• Array, []
• Type Coercion
• Composite Type
• Parameter
• Return
• Type Checking
• Void