# Constant

English (en) suomi (fi) français (fr) русский (ru) 中文（中国大陆）‎ (zh_CN)

A constant is a variable that does not change, it has a final value.

Constants are defined in the const section of a Free Pascal program. When a symbol is defined as constant, the Free Pascal compiler can often do some optimizations to make the output code faster or smaller.

Some special Free Pascal constants are:

Logical truth values

data type limits

The mathematical value π is realized as a function in system.pi.