CODEWITHSUNDEEP
javascriptregex
Prayag Sagar
Prayag Sagar

Reputation: 671

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

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 :

EDIT:

Valid values

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

Upvotes: 9

Views: 10356

Answers (4)

Thomas Ayoub
Thomas Ayoub

Reputation: 29471

I would use this

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

See demo and explanation

Upvotes: 1

Buh Buh
Buh Buh

Reputation: 7546

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.

Upvotes: 3

axelduch
axelduch

Reputation: 10849

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

Upvotes: 0

Wiktor Stribiżew
Wiktor Stribiżew

Reputation: 627507

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));
}

Upvotes: 4

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