The is_string() function is an inbuilt function in PHP which is used to check whether the given value is a string or not.
Syntax:
bool is_string( mixed $var )
Parameters: This function accepts one parameter as mentioned above and described below:
- $var: It contains the value that need to check.
Return Value: It returns TRUE if the value of variable is of string type and FALSE otherwise.
Program 1:
<?php   $str = "neveropen" ;   // Check value of variable is set or not if ( is_string ( $str )) {     echo "String" ; } else {     echo "Not String" ; }   $arr = array (10, 25.56, 'G' , true, 'Geeks' );   foreach ( $arr as $index ) {     if ( is_string ( $index )) {         echo "\nString" ;     }     else {         echo "\nNot String" ;     } }   ?> |
String Not String Not String String Not String String
Program 2:
<?php   $num = 21; var_dump( is_string ( $num ));   $arr = array (         "a" => "Welcome" ,         "b" => 2,         "c" => "neveropen"     );   var_dump( is_string ( $arr [ "a" ])); var_dump( is_string ( $arr [ "b" ])); var_dump( is_string ( $arr [ "c" ]));   ?> |
bool(false) bool(true) bool(false) bool(true)
Reference: https://www.php.net/manual/en/function.is-string.php