Addition, Subtraction, Multiplication, & Division
Description
These operators return the sum, difference, product, or quotient (respectively) of the two operands. The operation is conducted using the data type of the operands, so, for example, 9 / 4
gives 2
since 9 and 4 are ints. This also means that the operation can overflow if the result is larger than that which can be stored in the data type (e.g. adding 1 to a short with the value 32,767 gives -32,768). If the operands are of different types, the “larger” type is used for the calculation.
If one of the numbers (operands) are of the type float
or of type double
, floating point math will be used for the calculation.
Example
y = y + 3; x = x - 7; i = j * 6; r = r / 5;
Syntax
result = value1 + value2;
result = value1 - value2;
result = value1 * value2;
result = value1 / value2;
Parameters
value1
: any variable or constant
value2
: any variable or constant
Programming Tips
- Know that integer constants default to int, so some constant calculations may overflow.
- Choose variable sizes that are large enough to hold the largest results from your calculations.
- Know at what point your variable will “roll over” and also what happens in the other direction.
- For math that requires fractions, use float or double variables, but be aware of their drawbacks: large size, slow computation speeds.
- Use the cast operator e.g. (int)myFloat to convert one variable type to another on the fly.
The text of the 86Duino reference is a modification of the Arduino reference, and is licensed under a Creative Commons Attribution-ShareAlike 3.0 License. Code samples in the reference are released into the public domain.