Bounds Checking - Range Checking

Range Checking

A range check is a check to make sure a number is within a certain range, for instance that a value about to be assigned to say a sixteen-bit integer is within the capacity of a sixteen-bit integer. This is not quite the same as type checking. Other range checks may be more restrictive, for example a variable to hold the number of a calendar month may be declared to accept only the range 1 to 12. This is often used with arrays, as using a number outside of the upper range in an array may cause the program to crash, or may introduce security vulnerabilities (see buffer overflow). In Java, the interpreter automatically does a range-check when items in an array are accessed, and throws an exception if the item is out of range.