What does the prefix 0x signify in a number?

The prefix "0x" signifies that the number following it is in hexadecimal format. Hexadecimal is a base-16 numbering system that utilizes sixteen symbols: the digits 0 to 9 represent values zero to nine, while the letters A to F (or a to f) represent the values ten to fifteen.

For example, the hexadecimal number "0x1A" translates to the decimal value of 26. The "0x" prefix is a common notation used in programming and computer science to clearly indicate that the number is not in decimal (base-10), octal (base-8), or binary (base-2) formats. This clarity helps developers avoid confusion when working with different numeric systems, especially since hexadecimal is frequently used in contexts such as memory addresses and color codes in web design.

Other prefixes, such as "0o" for octal and "0b" for binary, serve specific purposes in distinguishing these other numbering systems, which clarifies the format being used and ensures accurate interpretation of the values.