is_string

Function • Params and return types changed in PHP 8.0

Find whether the type of a variable is string.

PHP 5
PHP 7
PHP 8.0
Improved
PHP 8.1
PHP 8.2
PHP 8.3
PHP 8.4
PHP 8.5

is_string Function synopsis

is_string(mixed $value): bool

Parameters

$value

Typemixed

The variable being evaluated.

Return value

Typebool

Returns true if $value is of type string, false otherwise.

Changes to the is_string Function

PHP 8.0

  • Return type added: bool
  • Parameter name of parameter #1 changed: $var to $value
  • Parameter type added for parameter #1 ($value): mixed
- is_string($var)
+ is_string(mixed $value): bool

is_string Function Availability

PHP VersionAvailability
PHP 8.5Future Release Yes
PHP 8.4Upcoming Release Yes
PHP 8.3Supported (Latest) Yes
PHP 8.2Supported Yes
PHP 8.1Security-Fixes Only Yes
PHP 8.0Unsupported Yes
PHP 7.4Unsupported Yes
PHP 7.3Unsupported Yes
PHP 7.2Unsupported Yes
PHP 7.1Unsupported Yes
PHP 7.0Unsupported Yes
PHP 5.6Unsupported Yes
PHP 5.5Unsupported Yes
PHP 5.4Unsupported Yes
PHP 5.3Unsupported Yes