Regex in javascript to allow only numbers, commas, and a single decimal point

Question

Currently i am using this regex to match for positive numbers with a single decimal point

/^\d+(\.\d+)?$/

But this doesn't allow commas. How can i modify this to allow zero or more commas before the decimal point?

Example :

• 11,111.00 (should be allowed) I am okay with numbers having any number of comma's before decimal point.

EDIT:

Valid values

• 111
• 11,111
• 11,111.0
• 111111

The values can be entered with or without comma. The datatype of this field is SQL MONEY, so it will handle comma's.

Answer 1

need

/^(?:\d{1,3}(?:,\d{3})*|\d+)(?:\.\d+)?$/

See the regex demo

Details

• ^ - start of string
• (?:\\d{1,3}(?:,\\d{3})*|\\d+) - Either of:
  • \\d{1,3}(?:,\\d{3})* - 1 to 3 digits followed with 0+ sequences of a , and 3 digits
  • | - or
  • \\d+ - 1 or more digits
• (?:\\.\\d+)? - an optional sequence of . and 1+ digits
• $ - end of string.

 var strs = [',,,,', '111', '11,111', '11,111.0', '111111']; var re = /^(?:\\d{1,3}(?:,\\d{3})*|\\d+)(?:\\.\\d+)?$/; for (var s of strs) { console.log(s + " => " + re.test(s)); } 

Answer 2

This is a very simple general solution, without any assumptions about how many digits are needed.

/^\d[\d,]*(\.\d+)?$/

[\\d,] will match digits or commas.
You could make the regex more complicated if you really need it to be more specific.

Answer 3

I would use this

^(?:\d{1,3}(,\d{3})*|\d+|\d{2}(?:,\d{2})*,\d{3})(?:\.\d+)?$

See demo and explanation

Answer 4

This is pretty hard to read but I'll explain it

/^(?:\\d+)(?:(?:\\d+)|(?:(?:,\\d+)?))+(?:\\.\\d+)?$/

All the ?: are just to explicitly say to the regex engine "Don't capture the following group matched by this paren).

The simplified version would be

/^(\\d+)((\\d+)|((,\\d+)?))+(\\.\\d+)?$/

But it'd capture a lot of matching groups for no reason so I removed them