We are independent & ad-supported. We may earn a commission for purchases made through our links.
Advertiser Disclosure
Our website is an independent, advertising-supported platform. We provide our content free of charge to our readers, and to keep it that way, we rely on revenue generated through advertisements and affiliate partnerships. This means that when you click on certain links on our site and make a purchase, we may earn a commission. Learn more.
How We Make Money
We sustain our operations through affiliate commissions and advertising. If you click on an affiliate link and make a purchase, we may receive a commission from the merchant at no additional cost to you. We also display advertisements on our website, which help generate revenue to support our work and keep our content free for readers. Our editorial team operates independently of our advertising and affiliate partnerships to ensure that our content remains unbiased and focused on providing you with the best information and recommendations based on thorough research and honest evaluations. To remain transparent, we’ve provided a list of our current affiliate partners here.

Our Promise to you

Founded in 2002, our company has been a trusted resource for readers seeking informative and engaging content. Our dedication to quality remains unwavering—and will never change. We follow a strict editorial policy, ensuring that our content is authored by highly qualified professionals and edited by subject matter experts. This guarantees that everything we publish is objective, accurate, and trustworthy.

Over the years, we've refined our approach to cover a wide range of topics, providing readers with reliable and practical advice to enhance their knowledge and skills. That's why millions of readers turn to us each year. Join us in celebrating the joy of learning, guided by standards you can trust.

What is an Integer Overflow?

By Jessica Susan Reuter
Updated: May 16, 2024

Integer overflow refers to the phenomenon that occurs in certain computer data types where their signs switch from positive to negative, or vice versa, when they reach the ends of their applicable ranges. In computer ranges, integer data types have circular ranges, and when they reach one end of their range, they immediately move to the other end of their range. This is also called integer overflow.

A signed integer can hold a range of values from -231 to (231) - 1. This integer cannot have a value of (-231) - 1; rather, the next number it increments to is at the other end of its range: (231 - 1). The change from negative to positive at the end of its range is an example of integer overflow. By the same token, an integer cannot have a value of 231; this value would instead switch to the other end of its range and become -231.

This overflow has significant consequences while programming. An array can only have as many indices in it as the integer type allows, and negative indices don't count. If a programmer attempts to create an array larger than the integer type allows, significant memory errors can occur because integer overflow would result in a negative index. This is especially dangerous in languages that don't have explicit bounds checking for arrays, like C++.

When integer overflow occurs, related types of overflow such as buffer overflow, heap overflow, and stack buffer overflow can occur. In all of these cases, the integer overflow acts to overwhelm memory structures with more data than those structures can conceivably hold. These overflows, in simple programs, don't often do much more than cause an invalid read or invalid write error. Manipulation of this problem by hackers, however, can engineer memory errors that can cause more serious problems.

In most simple programs, integer overflow is not a major problem. The limits of the integer type are sufficiently large enough that the overflow problem doesn't come into play unless a lot of data is being handled at once. In some cases overflow can be mitigated, as in the case of incrementing counters, by using a larger data type with a greater range. The larger data type could, in theory, eventually encounter the same overflow problem, but as data type ranges get larger, the chances of doing so get smaller. Each integer data type's range is at least twice the size of the next smallest, so there is ample room for additional data.

EasyTechJunkie is dedicated to providing accurate and trustworthy information. We carefully select reputable sources and employ a rigorous fact-checking process to maintain the highest standards. To learn more about our commitment to accuracy, read our editorial process.
Discussion Comments
EasyTechJunkie, in your inbox

Our latest articles, guides, and more, delivered daily.

EasyTechJunkie, in your inbox

Our latest articles, guides, and more, delivered daily.