Underflow and overflow of data
When the value of the variable is either too long or too small for the data type to hold, the problem of data overflow or underflow occurs. The largest value that a variable can hold depends on the machine. Since floating point values are rounded *** to the number of significant digits allowed, an overflow results in the largest possible real value whereas an underflow results in zero. C does not provide any warning or indication of integer overflow, it simply give erroneous result.
