0b0

0b0 is a binary literal used in many programming languages to denote the integer value zero. The prefix 0b (or 0B in some syntax) identifies the following digits as base-2. The literal 0b0 represents the decimal value 0; any sequence of binary digits after the prefix represents the corresponding value, with leading zeros allowed (for example, 0b0001 equals 1, 0b0000 equals 0).

Common uses include initializing zero-valued bitmasks, setting default flags, or serving as an example of binary notation. Binary literals facilitate expressing bitwise operations and mask patterns directly in source code.

Support for 0b-style literals varies by language. Modern languages such as Python, JavaScript (ES2015 and later), Rust, Go, and C++14 and later support binary literals with the 0b prefix; some also allow 0B, and many permit underscores to group digits (for example, 0b1010_0101).

Because 0b0 encodes zero, its value is zero regardless of the representation or underlying memory layout, provided the type is an integer.

See also: binary numeral system, binary literal, bitwise operations, hexadecimal literal 0x.