# Data Types, Literals and Variables

Literals |

Literals are numeric, string or hexadecimal values that are written directly into the program code - they cannot be modified at run time. While variables are meant to be changed during processing, literal values remain Read Only. Literals are commonly used to display messages, assign constants, or place initial values into variables.

Two formats are supported for the definition of numeric literals in PxPlus: simple numbers (signed, with/without decimal point) or floating point numbers (using scientific notation).

String literals consist of a series of ASCII characters contained within "" quotation marks.