PHP provides several operators we can use on numbers. Let’s start with two that are likely familiar: the addition (
+) and subtraction (
echo 5 + 1; // Prints: 6 echo 6.6 + 1.2; // Prints: 7.8 echo 198263 - 263; // Prints: 198000 echo -22.8 - 19.1; // Prints: -41.9
Most of the time, we don’t have to worry about which type of number we’re using. We can add a float to an integer, subtract an integer from a float, and so on.
One quirk is that operators will return integers whenever the result of the operation evaluates to a whole number. So
8.9 + 1.1 will return
10, an integer, and not
10.0 even though both of the operands in the calculation were floating point numbers.
Let’s do some adding and subtracting!
echo to print the number 12 to the terminal. The trick: use addition or subtraction to print a statement that evaluates to 12, and the number 12 can’t appear anywhere in your code!