How to Replace specific word in given string.

Question

User-919499280 posted

Hi,

I want to replace specific word in below given string. Please look out below small code.

DataTable dtURLs = new DataTable();

DataColumn s1 = new DataColumn("OldURL");

dtURLs.Columns.Add(s1);

 

DataRow row1 = dtURLs.NewRow();

row1[s1] = "https://www.google.com";

dtURLs.Rows.Add(row1);

 

DataRow row2 = dtURLs.NewRow();

row2[s1] = "https://www.google.com/services/";

dtURLs.Rows.Add(row2);

 

string campaignContent =

@"https://www.google.com <br/> https://www.google.com/services/";

string queryString = "queryString";

 

foreach (DataRow dr in dtURLs.Rows)

{

    string pattern = @String.Format(@"\b{0}\b", dr["OldURL"].ToString());

    campaignContent =

Regex.Replace(campaignContent, pattern, dr["OldURL"].ToString() + "?" + queryString);

 

}

 

I am trying above the model but I got wrong output like below.

OUTPUT:    

https://www.google.com?queryString <br/> https://www.google.com?queryString /services/

But I am excepted OUTPUT is like below.

https://www.google.com?queryString <br/> https://www.google.com/services/?queryString

Please give any solutions for above issue.

Answer 1

User1283497924 posted

For replacing specific work from a string you can use Replace function present in .net.

plz check eg;

string str="This is really new place.";
string newstr=str.Replace("new","old");

in above code we are replacing new word with old present in string

http://msdn.microsoft.com/en-us/library/fk49wtc1(v=vs.110).aspx

Answer 2

User1508394307 posted

Why not simply to add query string at the end?

//string pattern = @String.Format(@"\b{0}\b", dr["OldURL"].ToString());
//campaignContent = Regex.Replace(campaignContent, pattern, dr["OldURL"].ToString() + "?" + queryString);

campaignContent = dr["OldURL"].ToString() + "?" + queryString;

Answer 3

User-919499280 posted

Hi vinay,

i know above replace function. I want specific word for example if your word having 'is' two times right?

I want to replace 'is' word only in your sentence. U got my point.

here output is like below.

string newstr=str.Replace("are","is");

Result: Thare are really new place.

but i want below result.

This are really new place.

Answer 4

User-919499280 posted

HI Smirnov,

Actually my requirement is i have one template, It having lot of Links. I want to add tags(Google analytic tags) to end of each and every link that why i maintain all links in DataTable then looping it and changing one by one. It is fine but in my template having two links like below.

1. http://www.google.com

2. http://www.google.com/service.

I want to change only http://www.google.com to http://www.google.com?queryStirng don't disturb other links.

Answer 5

User1508394307 posted

string newstr=str.Replace("are","is");

Result: Thare are really new place.

but i want below result.

This are really new place.

In this case you should use 

string newstr=str.Replace("Thare","This");

Answer 6

User-919499280 posted

@vinay & @smirnov 

Thanks for reply here the brief explanation of my actual problem.

Actually my requirement is I have one template with lot of links. I get all links in one DataTable. I am looping that DataTable and replace each every link with Google analytics tag which is given by my client.

Here problem is in my template having two links like below.

1. http://www.google.com
2. http://www.google.com/services

I want to replace “ http://www.google.com “  to “ http://www.google.com?ClientTags “  don’t disturb other links. My problem is while replacing 2^nd link also replaced I am getting result like below

http://www.google.com?ClientTags  …… something matter …. http://www.google.com?ClientTags/Services

I want to replace only 1^st link only. I want to replace specific word.

Answer 7

User1508394307 posted

Why not simply do like this?

string search = "http://www.google.com";
string replace = "http://www.google.com?ClientTags";
int pos = text.IndexOf(search);
if (pos != -1)
   text = text.Substring(0, pos) + replace + text.Substring(pos + search.Length);

Answer 8

User-919499280 posted

Thanks for reply. It is working only when text contain one http://www.google.com working fine. But if your template having multiple http://www.google.com links above logic not working. For example like below.

text =@"http://www.google.com <br/> http://www.google.com/services/ <br/> http://www.google.com";

string search = "http://www.google.com";
string replace = "http://www.google.com?ClientTags";
int pos = text.IndexOf(search);
if (pos != -1)
   text = text.Substring(0, pos) + replace + text.Substring(pos + search.Length);

Answer 9

User1508394307 posted

First of all it is not clear why if you have all urls in the database you put them all in a string and then replace in that string. Instead you can do a loop through all rows and compare urls one by one.

If this is not possible for some reasons then you can try 

www.google.com(?![/\w])

Complete example: https://dotnetfiddle.net/HJxYVQ

Output: 

http://www.google.com?newstring <br/> http://www.google.com/services/ <br/> http://www.google.com?newstring

Answer 10

User-919499280 posted

Thank you very much smirov. Can you please given some reference site address of how to write above patterns.

Answer 11

User-919499280 posted

The above solution working fine. IF links having already parameters at that time above code not working. plz check below link.

https://dotnetfiddle.net/h6YsnP

http://www.google.com?newstring?UTM_Source=test This is wrong replacement. If Content links having with parameter  and with out parameters.

Answer 12

User1508394307 posted

If http://www.google.com?UTM_Source=test should not be replaced then add ? in [ ]

www.google.com(?![?/\w])