formatval

Formatval is a programming utility name used in several languages to convert a value into a formatted string according to a specified format. It is not a universal standard; the exact signature, capabilities, and naming vary by environment. In general, formatval takes a value and a format specification and returns a string suitable for display, logging, or storage.

Typical features include numeric formatting (fixed or scientific notation, precision, thousands separators), date and time formatting, alignment and padding, locale-aware rules, and escaping for safe output in templates. The format specification may be a string (for example, a printf-like directive) or a structured object defining fields such as width, alignment, fill character, and type. Implementations often provide options to control localization, padding character, and whether to truncate or round values.

Common variants include wrappers around printf-style formatting, components of template engines, or parts of data-serialization libraries. Some languages provide a built-in formatval function, while others supply it through standard libraries or third-party modules. Because the concept is broad and the exact API differs, users generally consult language-specific documentation to determine accepted format syntax and behavior.

Typical use cases involve producing human-readable output for consoles and logs, rendering values in user interfaces, and preparing strings for storage or transmission. Understanding the available specifiers and locale rules in the target environment is essential for correct and portable formatting.

See also: string formatting, locale-aware formatting, template engines, printf-style directives.