hexliterals

Hexliterals are literals that represent numeric values using hexadecimal notation. In many programming languages, a hex literal starts with a prefix such as 0x or 0X, followed by hexadecimal digits 0–9 and a–f (digits are case-insensitive). They typically denote integers and are commonly used for bit masks, addresses, color values, and other low‑level data representations.

Some languages also support hexadecimal floating-point constants, using forms like 0x1.921fb54442d18p+1 in C99, which denotes a floating-point value. Most languages additionally permit various size or signedness modifiers via suffixes such as U, L, UL, and variants specific to the language. In practice, hex literals provide a concise, machine-oriented way to write exact values.

Common examples include 0x2A (42) and 0xFF00 (65280). Hex literals are especially helpful when performing bitwise operations, defining color codes, or expressing hardware-related constants. Some languages support digit separators or underscores to improve readability within long hex literals, for example 0xFF_FF_00 in languages that implement numeric separators.

Caution is advised when mixing bases: in languages with an octal prefix, a value such as 0755 may be interpreted as octal rather than hex; the prefix 0x ensures hex interpretation. The value of a hex literal does not depend on endianness, though its in-memory representation may vary by architecture.

Hex literals are one of several ways to express numbers in base 16; others include hex-floating forms and, in some languages, alternative notations like $FF in assembly or binary literals in some high-level languages.