Useful static methods on the Char class

Yan Cui

I help clients go faster for less using serverless technologies.

Whilst reading through the answers for this question on StackOverflow, I came across the IsDigit and IsNumber methods on the Char class. And looking at the Char class in more detail there are many more useful methods on the Char class which I didn’t realise was there before, such as:

IsDigit checks if a character is a radix-10 digit, i.e. 0-9.

IsNumber checks if a character can be categorized as a number, including digits, characters, fractions, subscripts, currency numerators, etc.

GetNumericValue converts a character to a double.

GetUnicodeCategory categorizes a character into a group identified by one of the UnicodeCategory enum. This is an interesting method as it allows you to check whether a given character is a currency symbol or maths symbol for instance:

char.GetUnicodeCategory('+').Dump();  // UnicodeCategory.MathSymbol
char.GetUnicodeCategory('-').Dump();  // UnicodeCategory.DashPunctuation
char.GetUnicodeCategory('{').Dump();  // UnicodeCategory.OpenPunctuation
char.GetUnicodeCategory('$').Dump();  // UnicodeCategory.CurrencySymbol
char.GetUnicodeCategory('}').Dump();  // UnicodeCategory.ClosePunctuation

IsControl checks whether a character is a control character.

IsLetter checks whether a character is a unicode letter.

IsLetterOrDigit checks whether a character is a letter or a decimal digit.

IsLower and IsUpper checks whether a character is lower or upper case letter.

IsWhiteSpace checks if a character is a white space.

What’s even better, each of the methods are overloaded so that you can pass in the char to test or a string and an accompanying int to specify the position of the char in the string, e.g. IsDigit(char) and IsDigit(string, int).

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