Compound Arithmetic Operators (+= , -=, *=, /=)

These oparators perform a mathematical operation on a variable with another constant or variable. These operators are just a convenient shorthand:

x += y;   // equivalent to the expression x = x + y;
x -= y;   // equivalent to the expression x = x - y;
x *= y;   // equivalent to the expression x = x * y;
x /= y;   // equivalent to the expression x = x / y;

Here is an example:

int x = 2;
int y = 10;

x += 4;          // x now contains 6
x -= 3;          // x now contains 3
x *= y;          // x now contains 30
x /= 2;          // x now contains 15
x += max(20, 6); // x now contains 35
x -= sq(5);      // x now contains 15

Parameters

x: a numeric variable

y: a numeric variable, number constant, or any other expression that evaluates to a number (e.g. call to a function that returns a number).

See Also

• Arithmetic operators

License and Attribution

This documentation page was adapted from the Arduino Reference Documentation, which is released under a Creative Commons Attribution-ShareAlike 3.0 License.