Data type conversion
An operator must have
operands of the same type before it
can carry out the operation. Because of this, C will perform some automatic
conversion of data types.
These are the general rules for binary operators (* + / % etc):
If either operand is long double the other is converted to long
Otherwise, if either operand is double the other is converted to
Otherwise, if either operand is float the other is converted to
Otherwise, convert char and short to int
Then, if an operand is long convert the other to long.
cast to force a type conversion.