# Affix (natural sciences / computer science)

The name affix (. From the Latin ad-figere , "pin"; PPP : adfixum , assimilated to affixum ) has in linguistics (linguistics), the computer science , the mathematics and in the various sciences different meanings.

## Affixes in science

In the natural sciences, a well-defined set of prefixes is used in front of measured variables in order to obtain different orders of magnitude from a (measured) variable (e.g. meter , second , byte, hertz, joule ...) . See prefixes for units of measure .

## Affixes in computer science / mathematics

An affix in computer science or mathematics is, analogous to the definition in linguistics, part of a character string. Known prefixes , infix and postfix , the postfix for the correspondence suffix is in linguistics.

Let a, b, c,… be elements of an alphabet and let v, w be arbitrary strings over an alphabet. Then one denotes, for example, the substring ab in the character string

• abw as a prefix,
• vabw as infix,
• vab as a postfix.

As a result, an operation sign noted in different positions can be seen as an affix. For example, you can write the “+” operator as

• Prefix: + (m, n)
• Infix: m + n or
• Postfix: (m, n) +

For (arithmetic) operation signs, the infix notation is usually used : a + b ; for named functions mostly the Polish or prefix notation : f ( x ), g ( x , y ); the postfix notation can be found, for example, when entering into programmable pocket calculators: a b + .