numberwithdelimiter

numberwithdelimiter is a numeric formatting helper that inserts grouping delimiters into a number for improved readability, typically placing a separator every three digits to the left of the decimal point. It is commonly found in web frameworks and libraries; a well-known implementation is Ruby on Rails' ActionView::Helpers::NumberHelper#number_with_delimiter.

Typical behavior accepts integers and floats and returns a string with grouping delimiters applied while preserving the decimal portion without rounding. For example, number_with_delimiter(1234567.89) produces "1,234,567.89" when using the common U.S. conventions. The helper usually allows customization of the grouping character (delimiter) and the decimal marker (separator), and many implementations fall back to locale-specific defaults via internationalization settings.

Usage scenarios include formatting numbers for display in user interfaces, reports, and financial summaries where readability of large numbers is important. It is often paired with other numeric helpers that control precision, currency symbols, or human-readable scaling (e.g., number_with_precision, number_to_currency, number_to_human).

Implementations vary in edge-case handling (non-numeric inputs, nil values, negative numbers, and large decimals), so developers should consult the specific library or framework documentation for exact behavior, options, and localization integration.