Something else which you should bear in mind is that a program will not always detect when you exceed the range of a variable. If I put the value 255 into a variable of type byte this is OK, because 255 is the biggest possible value of the type can hold. However, if I add one to the value in this variable the system may not detect this as an error. In fact this may cause the value to "wrap round" to 0. Which could cause my program big problems.
