public function isTrue(): bool
    {
        return (
            in_array($this->string, ['ok']) ||
            (true === filter_var($this->string, FILTER_VALIDATE_BOOLEAN, FILTER_NULL_ON_FAILURE))
        );
    }
public function isTrue(): bool
    {
        return (
            in_array($this->string, ['ok']) ||
            (true === filter_var($this->string, FILTER_VALIDATE_BOOLEAN, FILTER_NULL_ON_FAILURE))
        );
    }
public function isTrue ( ) : bool { return ( in_array ( $ this -> string , [ 'ok' ] ) || ( true === filter_var ( $ this -> string , FILTER_VALIDATE_BOOLEAN , FILTER_NULL_ON_FAILURE ) ) ) ; }
Check if a given value can be perceived as true
Will on return true if the value "looks true-y"
"true", "1", "yes", "on", "ok"

@return bool
Check if a given value can be perceived as true Will on return true if the value looks true - y true 1 yes on ok