Why Does `(-2147483648 > 0)` Evaluate to True in C ?

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Why Does (-2147483648 > 0) Return True in C ?

This article explores a perplexing behavior in C where the expression (-2147483648 > 0) unexpectedly evaluates to true.

-2147483648, the smallest 32-bit integer, is represented as a positive value with the unary - operator applied. However, on platforms where long int and long long int lack a greater range than int, this value overflows the positive side of the integer range.

As a result, the compiler treats 2147483648 as an implementation-dependent negative value. This negative value becomes positive after applying the unary - operator, causing the expression to evaluate to true.

Alternatively, the implementation might use unsigned types to represent the value, leading to the same result. This behavior is undefined in C , and implementations are free to interpret the overflow in any manner they deem fit.

To avoid such anomalies, constants like INT_MIN are typically defined as (-2147483647 - 1) instead of -2147483648, ensuring that they correctly represent the minimum integer value.

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