/*
Extracts the last N digits from a given number.
Approach:
- To get the last N digits, compute: number % (10 ** digits)
- This avoids string manipulation and uses efficient arithmetic.
Parameters:
$number : the original integer
$digits : how many digits to extract from the end
Returns:
The last N digits as an integer.
*/
function getLastNDigits(int $number, int $digits): int
{
// Compute 10^digits using PHP's exponent operator (**)
$divisor = 10 ** $digits;
// Modulo returns the remainder, which is exactly the last N digits
return $number % $divisor;
}
// Example values
$number = 987654321;
$digits = 4;
// Extract the last N digits
$result = getLastNDigits($number, $digits);
// Display the result
echo "Original number: $number\n";
echo "Digits requested: $digits\n";
echo "Last $digits digits: $result\n";
/*
run:
Original number: 987654321
Digits requested: 4
Last 4 digits: 4321
*/
