Arithmetic Operations in Arduino Programming Language
Addition, Subtraction, Multiplication, & Division
Description
These operators (+, -, / & *) return the sum, difference, product, & quotient
(respectively) of the two operands, so they are binary operator. 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 an int 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, and the integer type will be suppressed.
Examples
y = y + 3; //add x = x - 7; //subtract i = j * 6; //multiply r = r / 5; //divide
Syntax
result = value1 + value2; //add result = value1 - value2; //subtract result = value1 * value2; //multiply result = value1 / value2; //divide
Parameters:
value1 & value2: any variable or constant of a particular type
Programming Tips:
- Know that integer constants default to int, so some constant calculations may overflow (e.g. 60 * 1000 will yield a negative result, refer to the cyclic property of signed integer).
- 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 e.g. (0 - 1) OR (0 - - 32768)
- For math that requires fractions, use float variables, but be aware of their drawbacks: large size, slow computation speeds ( as they require more storage space compared to integer type & more processing power is consumed when operating them )
- Use the typecast operator e.g. (int)floating_variable to convert one variable type to another over the run time
