numericonly

numericOnly is a term used in software development to describe a mode, flag, or parameter that restricts data to numeric characters. It is not a formal standard, but appears in various libraries, frameworks, and APIs as a convention to enforce digits-only input or processing.

In input validation, numericOnly means the value must consist exclusively of digits. In client-side validation, an example would be a function isNumericOnly(s) that returns true if s matches a regular expression such as ^[0-9]+$ or ^\d+$, depending on locale and requirements. In string processing, numericOnly can be used to strip a string down to its digits by removing all non-digit characters.

In user interfaces, numericOnly is often provided as an option of input components to guide users and simplify data handling. HTML5 supports similar behavior via inputMode="numeric" and pattern attributes such as pattern="^[0-9]+$" to constrain entries on some browsers.

Limitations include locale-specific decimal separators, signs, and grouping symbols; some implementations include decimal points or minus signs, but others treat digits strictly as 0–9. When applying numericOnly in data interchange, it is important to define the expected format (integer vs. real number) and locale rules.

See also: data validation, input masking, regular expressions.