Starting from PHP 7.0, PHP introduced support for return types in functions. Return types are used to specify the type of value that a function will return. They enhance code readability and allow the compiler to perform type checking.
To specify the return type of a function, you can use the : type
expression in the function declaration. Here are a few examples:
function addNumbers(int $a, int $b): int {
return $a + $b;
}
In the above example, the addNumbers
function indicates that it will return a value of type int
. If the function tries to return a value that is not of the specified type, an error will occur.
Here are some examples of return types you can use:
int
: Integer valuefloat
: Floating-point number valuestring
: String valuebool
: Boolean value (true or false)array
: Array valuevoid
: Used for functions that do not return any value
PHP also supports the use of the ?
symbol for return types. For example, the ?string
expression indicates that a function can return either a string value or null
.
Starting from PHP 8.0, keywords such as class
, interface
, static
, and self
can also be used for more complex return types.
Return types are beneficial, especially in large projects, as they improve code readability and facilitate debugging. However, return types are not mandatory and should be gradually added to existing codebases to maintain backward compatibility.