Plusmerkki

Plusmerkki, commonly called the plus sign in English, is the symbol '+' used to indicate addition, positive values, and various other operations. In Finnish, the term plusmerkki denotes this symbol itself. The sign is a standard operator in mathematics, science, computing, and everyday writing, appearing in places from arithmetic to programming language syntax.

Encoding and typography: The plus sign is represented in Unicode as U+002B and in ASCII as 0x2B. In UTF-8 it is encoded as the single byte 0x2B. A fullwidth variant exists for East Asian typography (U+FF0B) to align with other fullwidth characters. Typography can vary by font, but the general form is a cross with horizontal and vertical strokes intersecting near their centers.

Usage: In mathematics the plus sign denotes addition and positive values. In programming languages it commonly represents addition and, in many languages, string concatenation as well as unary plus to indicate a positive value. In regular expressions the plus acts as a metacharacter meaning “one or more” of the preceding element. It also appears in user interfaces to indicate actions such as adding items.

History: The plus sign has medieval European origins and appeared in arithmetic texts in the late 15th century. Its inventor is not known; it spread and became standard alongside the minus sign in early modern mathematics and typography. Over time, separate typographic forms emerged for different scripts and contexts, including the fullwidth version used in East Asia.

Related topics include the plus operator, Unicode, ASCII, regular expressions, and typography.