CODEWITHSUNDEEP
c#.netregex
user1263981
user1263981

Reputation: 3157

Regular expression for maximum value

I have come up with the following regexp to accept values with a .25 interval or in quarter format, like 1.25, 10.75, 11.50, 12, 13.

Regular Expression

^\d+((\.0+)*|(\.250*)|(\.50*)|(\.750*))$

Example

Accepted Values = 0, 0.25, 0.50, 0.75, 3 , 1.25 , 1.50, 1.75, 5 , 10

Not Accepted Values = 0.15, 0.20, 0.26, 0.30, 1.30, 1.55

I have the following questions;

  1. How can I make it not accept .25, but accept 0.25?

  2. How can I limit the value to the maximum number? I want it to accept up to 15.5.

Upvotes: 0

Views: 3862

Answers (6)

Orel Eraki
Orel Eraki

Reputation: 12196

I think Regex is the wrong way to do it, but if you insist then the following should suit you right.

^(\d|1[0-5]?)((\.0+)*|(\.250*)|(\.50*)|(\.750*))$

Upvotes: 0

Anna
Anna

Reputation: 759

^(0|1)?[1-4]?(|\.0+|\.250*|\.50*|\.750*)$ for matching 0-14 numbers and make a | to match with numbers 15, 15.25, 15.50* with the following:

15(|\.0+|\.250*|\.50*)

The final one will be

^(((0|1)?[1-4]?(|\.0+|\.250*|\.50*|\.750*)) | (15(|\.0+|\.250*|\.50*)))$

Upvotes: 0

Alireza MH
Alireza MH

Reputation: 593

You can use this regex:

^((?:1[0-4]|[0-9])?(?:\.(?:25|5|75))?0*|15(?:\.(?:25|5)?0*)?)$

Demo: http://regex101.com/r/eQ2pA1/7

Upvotes: 0

arco444
arco444

Reputation: 22841

This is the wrong way to do this, but a solution nonetheless:

^((1[0-4]|[0-9])?(\.(25|5|75)?0*)?|15(\.(25|5)?0*)?)$

Demo

Regex r = new Regex("^((1[0-4]|[0-9])?(\\.(25|5|75)?0*)?|15(\\.(25|5)?0*)?)$");
string[] arr = {".25", "17.545", "3.75000", "19.5", "10.500", "0.25"};

foreach(string s in arr) {
    if (r.IsMatch(s)) {
        Console.WriteLine(s);
    }
}

It gives:

.25
3.75000
10.500
0.25

Upvotes: 0

Gimly
Gimly

Reputation: 6175

In my opinion, Regex is not the correct tool for that kind of work. All the values you want to accept are decimal values. Simply parse the entered value as decimal and then check if it's correct regarding your accepted values:

decimal number;

if (Decimal.TryParse(value, out number))
   // Check if you're in the correct range

It will be much simpler, and errorproof.

Upvotes: 7

Anna
Anna

Reputation: 759

It's not accepting .25 as if you have a \d+ at the beginning which means that you are waiting at least one digital before ".". I think you could change \d+ by the following (0|1)?[1-5]? to accept till 15.

Regex details can be found here.

Upvotes: 0

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