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 = "GeeksforGeeks" ;
// 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" ;
}
} ?> |
Output:
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" => "GeeksforGeeks"
);
var_dump( is_string ( $arr [ "a" ]));
var_dump( is_string ( $arr [ "b" ]));
var_dump( is_string ( $arr [ "c" ]));
?> |
Output:
bool(false) bool(true) bool(false) bool(true)
Reference: https://www.php.net/manual/en/function.is-string.php