display value information inside a function? [closed]

How to output information about the value (1) in var_dump,
What is specified to search in str_contains?

$a = 1;
$b = str_contains($a, 1);  //value 1 for which to show information in var_dump

echo var_dump($b);        // prints bool(true) and not information about the value 1, 
                          // which is specified in the search