i32

i32 is a 32-bit signed integer type used in several programming languages and libraries. It represents whole numbers within the range -2,147,483,648 to 2,147,483,647 and requires four bytes of memory. On most platforms, signed 32-bit integers use two's complement representation, which provides a consistent way to perform arithmetic and bitwise operations.

In Rust, i32 is a primitive type and the canonical example of a 32-bit signed integer. The type name indicates its size, and literals can be annotated with a suffix such as 42i32. Similar fixed-width signed integer types exist in other languages, including i8, i16, i64 in Rust; and their equivalents in C/C++ (int32_t) and many other ecosystems (such as Java’s int or Swift’s Int32).

i32 is commonly used wherever a fixed-width, small-range signed integer is appropriate. It is frequently employed for counters, array indexing, and numeric computations where predictable overflow behavior or memory usage is important. The four-byte size makes it a good match for performance-critical code that needs a stable, platform-independent integer width.

Overflow and behavior on exceeding the range are language-specific. For example, Rust performs checked overflow in debug builds and wrapping on release builds; C and C++ treat signed overflow as undefined behavior; Java wraps around using two's complement semantics. Because of these differences, developers must consider language-specific rules when performing arithmetic near the limits of i32.

See also: i8, i16, i64, u32, int32_t, and related fixed-width integer types.