What does this line of code mean?

Question

if(!is_numeric($num1) || !is_numeric($num2)){

echo 'Please enter the numerical type';
}

Answer 1

is_numeric() function is used to detect whether a variable is a number or a numeric string.

Answer 2

If either $num1 or $num2 is not a number or a numeric string, print a prompt message telling you that you need to enter a numeric type.