decimaltegn

Decimaltegn, or decimal separator, is the symbol used to separate the integer part of a number from its fractional part in decimal notation. It is a core element of how numbers with fractions are written and read in many cultures and programming contexts.

Locale variation is common. In Danish usage, the decimal separator is a comma, and the period is typically used as a thousands separator (for example, 1.234,56 means one thousand two hundred thirty-four and fifty-six hundredths). In contrast, English-speaking countries usually use a period as the decimal separator and a comma as the thousands separator (for example, 1,234.56). Some languages also use a space as a thousands separator, with a comma as the decimal separator.

Implications for software and data exchange are important. The interpretation of a number like 1,23 or 1.234 can change with locale settings, so software often relies on locale information to display and parse numbers correctly. When data is shared across different regions, it is common to use a consistent format or to specify the locale, or to employ a neutral representation such as the decimal point in code and data files.

In programming, the decimal point (a dot) is typically used in source code across many languages (for example, 3.14), while locale-aware input/output can format numbers according to regional conventions. Understanding decimaltegn and its regional variations helps prevent misinterpretation in both everyday use and technical applications.