Matching numbers with regular expressions — only d

Question

I can't figure out how to construct a regex for the example values:

123,456,789
-12,34
1234
-8

Could you help me?

Answer 1

Try this:

^-?[\d\,]+$

It will allow an optional - as the first character, and then any combination of commas and digits.

Answer 2

For the examples:

    ^(-)?([,0-9])+$

It should work. Implement it in whichever language you want.

Answer 3

^-?    # start of line, optional -
(\d+   # any number of digits
|(\d{1,3}(,\d{3})*))  # or digits followed by , and three digits
((,|\.)\d+)? # optional comma or period decimal point and more digits
$  # end of line

Answer 4

In java, You may use java.util.Scanner with its useLocale method

Scanner myScanner =  new Scanner(input).useLocale( myLocale)

isADouble = myScanner.hasNextDouble()

Answer 5

Try this:

    boxValue = boxValue.replace(/[^0-9\.\,]/g, "");

This RegEx will match only digits, dots, and commas.

Answer 6

Try this:

^-?\d{1,3}(,\d{3})*(\.\d\d)?$|^\.\d\d$

Allows for:

1
12
.99
12.34 
-18.34
12,345.67
999,999,999,999,999.99