Validate number using regular expression in java

Question

Can anyone help me for validation of numbers like:

1,478.25

Special characters like . And , are only allowed

(@#$_&-+()/"':;!?~`|•√π÷×¶={} not allowed )*.

This is the regex I have tried so far:

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

Your help will be appreciated. Valid number are 123.45 1,234.5 and 0.01

You said "numbers like", what other forms should be accepted? Is `123` number valid or should it be `123.00`? Is `1,2345.00` valid? Or `.01`? Do you want to accept only two decimal places or can it change? — Pshemo, Dec 26 '17 at 09:25
Update your post to include rules you use to decide what is valid and what is not. — Pshemo, Dec 26 '17 at 09:29
"Yes number u have mentioned are valid" I also mentioned `1,2345.00` which has four digits after `,`. So can we assume that `,` can have any number of digits after it like `1,2,3,4,5,6.00`? Would such number be valid or there is some *rule* which invalidates it? If so what rule is it? — Pshemo, Dec 26 '17 at 09:34
@pshemo 1,2,3,4.00 is not valid...my current rule is I just want only one decimal value and accept comma..in text field. — , Dec 26 '17 at 09:39

cнŝdk · Accepted Answer · 2017-12-26T14:27:08.033

This is the regex you need: ^(\\d{1,3},)*(\\d{1,3})(.\\d{1,3})?$ along with the global and multiline flags.

This is how should be your code:

final String regex = "^(\\d{1,3},)*(\\d{1,3})(\\.\\d{1,3})?$";
final String string = "1,478.25\n"
     + "1,450\n"
     + "48.10\n"
     + "145.124.14";

final Pattern pattern = Pattern.compile(regex, Pattern.MULTILINE);
final Matcher matcher = pattern.matcher(string);


while (matcher.find()) {
    System.out.println("Full match: " + matcher.group(0));
}

This is a live Demo.

Sejal Rudani · Answer 2 · 2017-12-26T10:31:18.950

0

Please use below regular expression to validate numeric value with one decimal and multiple comma

      String num="1,335.25";

        String exp ="^[-+]?[\\d+([,]\\d+)]*\\.?[0-9]+$";

        if(num.matches(exp)){  
            System.out.println("valid number");
        }else{
            System.out.println("Not a valid number");
        }

Please check this one.

edited Dec 26 '17 at 10:31

answered Dec 26 '17 at 10:03

Sejal Rudani

372
4
19

Please check edited ans for multiple comma and single dot – Sejal Rudani Dec 26 '17 at 10:19
Yes if I put number as 0.01 – Dec 26 '17 at 10:30
Thanks sejal for your help as my reputation is not up to mark I am not able to mark ans as correct...thank you once again... – Dec 26 '17 at 10:34
currently I am facing issue for entering negative values can you please help me... – Jan 10 '18 at 06:24

score 0 · Answer 3 · answered Dec 26 '17 at 22:14

0

I think this regex is what you need

^\d{1,}(,\d+)?\.\d+$

answered Dec 26 '17 at 22:14

BullyBoo

52
4

Validate number using regular expression in java

3 Answers3