Regex to find a specific string

Question

I am trying to find the word "Amount" within the following list of words:

WaterAmount 
DamageAmount 
AmountOwed

I tried to use regex, but the following doesn't work:

Regex.IsMatch(name, @"\Amount\")

Can someone please help me to figure out how to do this?

Thank you.

Update:

Code being used:

foreach (string name in Request.Form.AllKeys)
        {

            if (Regex.IsMatch(name, "Amount"))
            {
                Response.Write(Request.Form[name]);
            }
            else
            {
                Response.Write("Not working\n");
            }

        }
}

Why do you need regex? You can just do `foo.Contains("Amount")` — DGibbs, Nov 20 '13 at 16:15
@BradHazelnut, that makes no sense. Those strings contain "Amount"??? — Liam, Nov 20 '13 at 16:17
Provide more example code of what you tried. This is probably an XY problem. http://meta.stackexchange.com/questions/66377/what-is-the-xy-problem — Plasmarob, Nov 20 '13 at 16:17
I am trying the following foreach (string name in Request.Form.AllKeys) { if (Regex.IsMatch(name, "Amount")) { Response.Write(Request.Form[name]); } else { Response.Write("Not working\n"); } } I also tried if (name.Contains("Amount")) and that didn't work either — Brad Hazelnut, Nov 20 '13 at 16:23
Modify this: `Response.Write("Not working\n");` to `Response.Write(string.Format("\"{0}\" - did not match", name));` and update your question with the output. — Austin Salonen, Nov 20 '13 at 16:35

Plasmarob · Accepted Answer · 2013-11-20T16:43:13.947

Instead of using regex, use:

name.Contains("Amount")

this should return a boolean as to whether Amount is in the string.

You don't need regex for this situation (and sometimes it's good to go without when unnecessary)

as others suggested,

name.IndexOf("amount", StringComparison.OrdinalIgnoreCase) >= 0;

could also be used to include "AMOUNT", "amount", "AmOunT", etc.

Or:

name.IndexOf("amount", StringComparison.OrdinalIgnoreCase)!= -1

We're just checking that IndexOf doesn't send back -1 for 'not found'.

The reason you might not want to use:

name.ToLower().Contains("amount")

is because it will have problems with international characters (accents, etc). If you were passing in a variable that could have any text, that could pose a problem. For a case with a constant string, it might be fine, however (though not extremely recommended)

Edit:

If I understand C# correctly (not my expertise, though i've used it), this should work:

foreach (string name in Request.Form.AllKeys)
{
    if (name.IndexOf("amount", StringComparison.OrdinalIgnoreCase) >= 0)
    {
        Response.Write(Request.Form[name]);
    }
    else
    {
        Response.Write("Not working\n");
    }
}

I see an extra brace in your code. Is that supposed to be there?

`name.IndexOf("amount", StringComparison.OrdinalIgnoreCase) >= 0` is better for case insensitive `Contains`. Check [this answer](http://stackoverflow.com/a/444818/393487) — Ahmed KRAIEM, Nov 20 '13 at 16:22

score 1 · Answer 2 · answered Nov 20 '13 at 16:18

1

I think your approach is correct. I would suggest one minor change for it to work...

Regex.IsMatch(name, @"Amount")

Good Luck!

answered Nov 20 '13 at 16:18

gpmurthy

2,397
19
21

Jeroen Vannevel · Answer 3 · 2013-11-20T16:24:23.653

0

var index = name.IndexOf("Amount", 0, name.Length);

This will get you the index of the first occurrence. If you want all of them, just loop trough the text.

To ignore case sensitivity;

var index = name.IndexOf("Amount", 0, StringComparison.OrdinalIgnoreCase);

And if there's no match, IndexOf returns -1.

If you just want to know if your string is in there, use .Contains().

edited Nov 20 '13 at 16:24

answered Nov 20 '13 at 16:17

Jeroen Vannevel

43,651
22
107
170

Regex to find a specific string

3 Answers3