Integer overflow

Integer overflow occurs in computers, when the number which is stored becomes larger than the capacity of the memory it is stored in. The most likely result is that the number will reset to 0 and start over.

For example, start with the number 14, using 4-bits integers. Add 1 a few times, this will result in an overflow, which causes it to reset the number to 0.
 Binary number  Decimal number 1110  14 1111  15 0000  0 0001  1
Another result is the number will reset to the most negative number, if the number has a sign. This is because negative numbers are represented by values after the maximum positive value.

For example, with signed 4-bit integers. Adding 1 will cause this type of overflow:
Binary number  Decimal number01106 0111  7 1000  -8 1001  -7

References

Category:Computing