Solved

Invert the case of a mixed case string (can I use regex?)

Posted on 2006-06-26
8
910 Views
Last Modified: 2008-01-09
Hi,

I have a string that contains a mixed bag of upper and lowercase letters.

I need to invert these (upper to lower, lower to upper) so my question is do I have to iterate through each letter and swap it or can I use a smaller, cleaner method (perhaps using a regex expression??).

Many thanks.

James.
0
Comment
Question by:JAMES
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
8 Comments
 
LVL 10

Expert Comment

by:dkloeck
ID: 16983403
i gess you will have to iterate thrtough each char, because there is no method to invert the case of the letters in string
0
 
LVL 13

Accepted Solution

by:
devsolns earned 500 total points
ID: 16983434
Put this in a method or what have you,

                string text = "SoMe CaMEL cAse TEXT.";
                char[] textarray = text.ToCharArray();
                for(int i = 0; i < textarray.Length; i++)
                {
                    if((int)textarray[i] >= 65 && (int)textarray[i] <= 90)
                        textarray[i] = (char)((int)textarray[i] + 32);
                    else if ((int)textarray[i] >= 97 && (int)textarray[i] <= 122)
                        textarray[i] = (char)((int)textarray[i] - 32);
                }
                string newText = new string(textarray);
0
 
LVL 2

Expert Comment

by:Naishal
ID: 16983458
Regular Expression is basically to model the condition or pattern and use that RegEx to check the input and decide if that satisfies the pattern or condition you want it to.

If you dont want to compare string in turn, You can Consider the use of BitMasking going to the Byte Level.
0
Independent Software Vendors: We Want Your Opinion

We value your feedback.

Take our survey and automatically be enter to win anyone of the following:
Yeti Cooler, Amazon eGift Card, and Movie eGift Card!

 

Author Comment

by:JAMES
ID: 16983516
OK - accepting there is no regex expression and no intrinsic method Dev's method works great - thank you!

Many thanks for your help dk but I am sure you will understand if i give the points to Dev for a such a detailed answer.

James.
0
 
LVL 7

Expert Comment

by:pradeepsudharsan
ID: 16983526
     string s="ABcdEFgh";
                  char []c=s.ToCharArray();                  
                int c1=0;
                  for(c1=0;c1<c.Length;c1++)
                  {
                        
                        if(char.IsLower(c[c1]))
                              c[c1]=(char)((int)c[c1]-32);
                        else if(char.IsUpper(c[c1]))
                              c[c1]=(char)((int)c[c1]+32);
            
                  }
                  s=new string(c);
                  MessageBox.Show(s);
0
 
LVL 13

Expert Comment

by:devsolns
ID: 16983922
pradeepsudharsan & everyone,


my implementation of the method runs on average 60% faster than pradeepsudharsan version using the IsLower & IsUpper methods.


Test using 1 million iterations of a couple hundred length string.

-my version
1296 ms
1268 ms
1353 ms

avg:1305 milliseconds


-version using ToUpper & ToLower
2181 ms
2165 ms
2152 ms

avg:2166  milliseconds
0
 
LVL 13

Expert Comment

by:devsolns
ID: 16983930
Kinda suprised by the diff in speed.
0
 

Author Comment

by:JAMES
ID: 16983942
Thanks for the test results.
0

Featured Post

SharePoint Admin?

Enable Your Employees To Focus On The Core With Intuitive Onscreen Guidance That is With You At The Moment of Need.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

In order to hide the "ugly" records selectors (triangles) in the rowheaders, here are some suggestions. Microsoft doesn't have a direct method/property to do it. You can only hide the rowheader column. First solution, the easy way The first sol…
This article describes a simple method to resize a control at runtime.  It includes ready-to-use source code and a complete sample demonstration application.  We'll also talk about C# Extension Methods. Introduction In one of my applications…
There's a multitude of different network monitoring solutions out there, and you're probably wondering what makes NetCrunch so special. It's completely agentless, but does let you create an agent, if you desire. It offers powerful scalability …
In this brief tutorial Pawel from AdRem Software explains how you can quickly find out which services are running on your network, or what are the IP addresses of servers responsible for each service. Software used is freeware NetCrunch Tools (https…
Suggested Courses

624 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question