git add .

git commit -m <file name>

-m

git log

Author: User's name<User's.e-mai@example.com>

git init

git status

echo validatePIN("1234")."\n";
echo validatePIN("12345")."\n";
echo validatePIN("123456")."\n"; 
echo validatePIN("")."\n";

function validatePIN($pin){
	$len=strlen($pin);
	if (strlen($pin)!=4 && strlen($pin)!=6){
		return "PIN is invalid";
	}
	for ($i=0; $i<$len; $i++)
	$ASCII=ord($pin[$i]);
	if (!(47<$ASCII && $ASCII<58)){
		return "PIN is invalid";
	}
	return "PIN is valid";
}

/*
// a number "n" is automorphic if n^2 ends with "n"
e.g. 5 is automorphic number, because 5^2=25 ends with 5, 6^2=36 and is automorphic as well;
*/

echo "5 - ".isAutomorphic_2(5)."\n";    // 25
echo "8 - ".isAutomorphic_2(8)."\n";    // 64
echo "76 - ".isAutomorphic_2(76)."\n";  // 5,776

function isAutomorphic($num){
	$square=$num*$num;
	
	$result=str_ends_with($square, $num);
	return $result;
}


//using substring function
function isAutomorphic_2($num){
	return substr($num*$num, -1*strlen($num)) === strval($num);
}