Desimaalipilkku

Desimaalipilkku is the symbol used to separate the integer part from the fractional part of a decimal number. It is represented by the dot character ".". In Finnish everyday writing the standard decimal separator is the decimal comma (","). The desimaalipilkku is therefore most commonly encountered in international contexts, in English-language texts, and in computer programming, where the dot functions as the decimal separator.

Usage and locale differences are a key feature of the desimaalipilkku. In Finland and many other European countries, numbers are written with a comma for the fractional part (for example, 12,75). The dot is primarily used in contexts involving English-language conventions, international data formats, and software development.

In computing and programming, the desimaalipilkku is the default decimal separator in many languages, including C, Java, Python, JavaScript, and many data formats like JSON and CSV (often in locale-invariant form). This means numeric literals such as 3.14 or 0.001 are written with a dot, regardless of the reader’s locale. In contrast, user interfaces and printed documents in Finnish may display numbers with a comma.

Practical implications include locale-aware data entry and formatting, software localization, and the potential need to convert between decimal comma and decimal point when exchanging data internationally. When sharing numbers with Finnish audiences for formal writing, the decimal comma is usually preferred; in code and international data, the decimal point is standard.

Desimaalipilkku thus denotes the dot used as a decimal separator in many technical and international contexts, while the comma remains standard in Finnish non-technical writing.