Java validating strings for digits
After that there can be zero or more groups composed of a comma and exactly three digits.It ends with an optional group composed of a decimal and two digits.Data representing money are generally handled as floats since it is customary to leave out formatting characters.Yet, a developer may have an occasion where accepting formatted currency is required.A valid integer value should contain only digits and possibly a leading minus or plus sign.A regular expression to check that would look like this: These regular expressions are similar to the three above.The second regular expression is nearly the same as the first with one difference.It not only allows leaving off the cents, but will accept part of a decimal: the decimal point followed by zero, one, or two digits.
However, it is a good idea to trim data before validating using alltrim covered previously. Is Match to validate that a string is either empty, or exactly 4 characters (digits) in length.In other words, the strings, "", and "1234" should pass, whereas "123", "abcd", and "12345" should fail. Is Match(str, "[0-9]^4")) return true; but this does not work. Is Match("1234", @"\d\d\d\d") come close, but also result in "12345" validating. Hi Byron, You have to use ^ and $ to indicate start and end of the string: Regex.These were, however, still strings since the results of any mathimatical operation using them is meaningless. Numerical data is alway handled as string representations of numbers in (X)HTML forms or when the data is sent to the server.This allows some string based tests to verify that the string's pattern matches acceptable numeric data. Said another way: only an unsigned (positive) whole number.