Integers

Integer Literals

integer_literals.zig

const decimal_int = 98222;
const hex_int = 0xff;
const another_hex_int = 0xFF;
const octal_int = 0o755;
const binary_int = 0b11110000;
// underscores may be placed between two digits as a visual separator
const one_billion = 1_000_000_000;
const binary_mask = 0b1_1111_1111;
const permissions = 0o7_5_5;
const big_address = 0xFF80_0000_0000_0000;

Runtime Integer Values

Integer literals have no size limitation, and if any undefined behavior occurs, the compiler catches it.

However, once an integer value is no longer known at compile-time, it must have a known size, and is vulnerable to undefined behavior.

runtime_vs_comptime.zig

fn divide(a: i32, b: i32) i32 {
    return a / b;
}

In this function, values a and b are known only at runtime, and thus this division operation is vulnerable to both Integer Overflow and Division by Zero.

Operators such as + and - cause undefined behavior on integer overflow. Alternative operators are provided for wrapping and saturating arithmetic on all targets. +% and -% perform wrapping arithmetic while +| and -| perform saturating arithmetic.

Zig supports arbitrary bit-width integers, referenced by using an identifier of i or u followed by digits. For example, the identifier i7 refers to a signed 7-bit integer. The maximum allowed bit-width of an integer type is 65535. For signed integer types, Zig uses a two’s complement representation.

See also:

• Wrapping Operations