How can PHP be used to determine the largest number from a set of three different numbers?

To determine the largest number from a set of three different numbers in PHP, you can use the max() function which returns the highest value from a list of arguments. You can pass the three numbers as arguments to the max() function to find the largest number.

$num1 = 10;
$num2 = 20;
$num3 = 15;

$largest = max($num1, $num2, $num3);

echo "The largest number is: " . $largest;