How to replace a word in a string

Question

It is very basic question but i am not sure why it is not working. I have code where 'And' can be written in any of the ways 'And', 'and', etc. and i want to replace it with ','

I tried this:

and.Replace("and".ToUpper(),",");

but this is not working, any other way to do this or make it work?

That is equivalent to `and.Replace("AND", ",")`. In any case, look at Regex.Replace and case-insensitivity mode. — , Sep 21 '12 at 00:48
As @pst mentioned, you can use regex too: `var regex = new Regex( "camel", RegexOptions.IgnoreCase ); var newSentence = regex.Replace( sentence, "horse" ); ` code take from: http://stackoverflow.com/questions/6025560/how-to-ignore-case-in-string-replace — Jack, Sep 21 '12 at 00:50
You can also use the "(?i)and" option in the search pattern. This way you can use the static `Replace()` method since you don't need to use the `RegexOption.IgnoreCase` enum. I gave some code below. — Matt Klein, Sep 21 '12 at 01:10
You should consider that sentence can contain words like 'sand'. The Regex will replace them as well. That's not correct. — horgh, Sep 21 '12 at 01:24
I've made an StringExtensions project that provides an overload of Replace taking a ComparisonType, see: http://stringextensions.codeplex.com/SourceControl/changeset/view/66ba3d678467#src%2fStringExtensions%2fCommonStringExtensions.Replace.cs Now, you can simply say: `mystring.Replace("and", ",", StringComparison.InvariantIgnoreCase);` which is way more performant than any regex solution — Polity, Sep 21 '12 at 02:22

Neverever · Accepted Answer · 2012-09-25T07:22:46.107

6

You should check out the Regex class

http://msdn.microsoft.com/en-us/library/xwewhkd1.aspx

using System.Text.RegularExpressions;

Regex re = new Regex("\band\b", RegexOptions.IgnoreCase);

string and = "This is my input string with and string in between.";

re.Replace(and, ",");

edited Sep 25 '12 at 07:22

answered Sep 21 '12 at 00:50

Neverever

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Good use of `\b` (+1). I prefer to use the Regex static methods, but that's mostly just preference .. – Sep 21 '12 at 02:48

score 2 · Answer 2 · answered Sep 21 '12 at 00:51

2

words = words.Replace("AND", ",")
             .Replace("and", ",");

Or use RegEx.

answered Sep 21 '12 at 00:51

lahsrah

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He haven't mentioned in fact, but I think that you must to consider `And`, `aNd` `ANd` inputs etc. So, converts the input string and search string to even case and do the replace, or use only regex. – Jack Sep 21 '12 at 00:57
@Jack Yea that was just an example. I mean he could continue to chain the .Replace methods on or your RegEx as I mentioned. Since its just a limited number of combinations .Replace isn't that bad. – lahsrah Sep 21 '12 at 01:00

score 2 · Answer 3 · answered Sep 21 '12 at 00:54

2

The Replace method returns a string where the replacement is visible. It does not modify the original string. You should try something along the lines of

and = and.Replace("and",",");

You can do this for all variations of "and" you may encounter, or as other answers have suggested, you could use a regex.

answered Sep 21 '12 at 00:54

K Mehta

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While true, this will not help with "Jack And Jill". – Sep 21 '12 at 02:48

horgh · Answer 4 · 2012-09-21T01:27:17.760

I guess you should take care if some words contain and, say "this is sand and sea". The word "sand" must not be influenced by the replacement.

string and = "this is sand and sea";

//here you should probably add those delimiters that may occur near your "and"
//this substitution is not universal and will omit smth like this " and, " 
string[] delimiters = new string[] { " " }; 

//it result in: "this is sand , sea"
and = string.Join(" ", 
                  and.Split(delimiters,  
                            StringSplitOptions.RemoveEmptyEntries)
                     .Select(s => s.Length == 3 && s.ToUpper().Equals("AND") 
                                     ? "," 
                                     : s));

I would also add smth like this:

and = and.Replace(" , ", ", ");

So, the output:

this is sand, sea

Matt Klein · Answer 5 · 2012-09-21T01:08:36.040

0

try this way to use the static Regex.Replace() method:

and = System.Text.RegularExpressions.Regex.Replace(and,"(?i)and",",");

The "(?i)" causes the following text search to be case-insensitive.

http://msdn.microsoft.com/en-us/library/yd1hzczs.aspx

http://msdn.microsoft.com/en-us/library/xwewhkd1(v=vs.100).aspx

edited Sep 21 '12 at 01:08

answered Sep 21 '12 at 00:56

Matt Klein

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How to replace a word in a string

5 Answers5