String Equality - What is going on here? [closed]

Question

In order to debug an issue in my code, I have declared the following two strings, assuming they would be equivalent:

String print = "8A9B485ECDC56B6E0FD023D6994A57EEC49B0717";
String newPrint = thumbprint.Trim().Replace(" ", "").ToUpper();

I discovered they are not. Great, this is the source of my issue. However, I'm checking things in the immediate window (on the line following the declarations) and don't understand what is happening. Here is the output:

print
"8A9B485ECDC56B6E0FD023D6994A57EEC49B0717"
newPrint
"‎8A9B485ECDC56B6E0FD023D6994A57EEC49B0717"
String.Compare(print, newPrint);
0
print == newPrint
false
print.Equals(newPrint)
false

huh? Why aren't they equal?

edit:

I need to use 'thumbprint' as the base. It's a user entered string. I'm just using 'newPrint' as a temporary variable to hold the trimmed/uppered value. print is the expected outcome.

Answer 1

Indeed, they are not equivalent. I copied the two values and newPrint has a length of 41 whereas print has a length of 40. The first character of newPrint is a character with the ASCII value 14. Interesstingly, this has been transfered from your immediate window to SO to my LINQPad.

print.Length
40
newPrint.Length
41
(sbyte)print[0]
56
(sbyte)newPrint[0]
14

That actually has nothing to do with your Trim and Replace calls but with the fact that you are using thumbprint instead of print as the base. I can only assume that thumbprint contains that additional character. Where it comes from I don't know. If you would change your second line to use print instead of thumbprint you would get the result you expect.

Answer 2

The strings that you're posted are not equal. Just do this:

string val   = "8A9B485ECDC56B6E0FD023D6994A57EEC49B0717"; 
string val1  = "‎8A9B485ECDC56B6E0FD023D6994A57EEC49B0717";
var bt = System.Text.Encoding.UTF8.GetBytes(val);
var bt_1 = System.Text.Encoding.UTF8.GetBytes(val1);

You will see that the second array contains more element in begining.

226 
128 
142

after this 3 elements content is equal.

The reason String.Compare works is cause:

The comparison uses the current culture to obtain culture-specific information such as casing rules and the alphabetic order of individual characters