GetNumericValue

GetNumericValue is a name used for a character-oriented function in several programming libraries. It provides the numeric value associated with a single Unicode character, rather than parsing multi-character numbers from strings. Implementations differ between languages, but the common purpose is to expose the underlying numeric value defined by Unicode data for a character.

In .NET, Char.GetNumericValue(char c) returns a double. The value corresponds to the numeric value assigned to the character by Unicode. If the character has no numeric value, the method returns -1.0. Typical digits '0' through '9' yield 0 to 9, while other numeric characters—such as fractions, roman numerals, or numerals from other scripts—may yield fractional or larger values. This method is a low-level helper and does not perform string parsing or multi-character number construction.

In Java, Character.getNumericValue(char ch) returns an int. It also follows Unicode data: decimal digits yield 0–9, while certain letters and other numeric symbols yield values 10 and above. If the character has no numeric value, the method returns -1. This function is similarly a Unicode data lookup and is not intended for direct parsing of numeric strings.

Usage considerations include recognizing that not all characters are numeric and results depend on Unicode data and library version. For converting entire strings to numbers, language-specific parsing methods should be used (such as Convert or parsing utilities in .NET, or Integer.parseInt / Double.parseDouble in Java). GetNumericValue is most appropriate for inspecting or normalizing individual characters' numeric values.