function CheckPasswordStrength($password)
{
    
    $strength = 0;
    $patterns = array('#[a-z]#','#[A-Z]#','#[0-9]#','/[¬!"£$%^&*()`{}\[\]:@~;\'#<>?,.\/\\-=_+\|]/');
    foreach($patterns as $pattern)
    {
        if(preg_match($pattern,$password,$matches))
        {
            $strength++;
        }
    }
    return $strength;
    
    // 1 - zayif
    // 2 - zayif degil
    // 3 - kabul edilebilir
    // 4 - guclu
}

//usage
CheckPasswordStrength('password'); //1
CheckPasswordStrength('Password'); //2
CheckPasswordStrength('P4ssword'); //3
CheckPasswordStrength('P4ssw()rd'); //4