altering strings in C# - Overclock.net

DanNEBTD · 01-30-08

I am writing an ASP.Net web-page for class and want to make it so that I can have the page after the user enters a credit card number display only the last 4 digits. I know in C++ it was something like:

Code:

CCNumber.substr(11,15)

that could make a credit card number of 1234 5678 9012 3456
into a credit card number of: 3456.

I would then be able to just put a string of ** in front of it.

so long story short. what is the C# (or asp.net) equivalent of the .substr()?

exitmusic · 01-30-08

That's odd... I was under the impression that .Substr() worked in C#. You could always try removing unwanted characters using .Remove()

DanNEBTD · 01-30-08

hmm . . . maybe it does . . i should have double checked. . . I know its not in auto complete.

DanNEBTD · 01-30-08

OMG. . . im an IDIOT . . mod feel free to close thread or ban me for being ignorant

(misspelled the friggin variable)

exitmusic · 01-30-08

happens to the best of us

DanNEBTD · 02-15-08

Still having the problem . . . when I try to alter the credit card string to only diplay the last 4 Digits using the following code I get an error. . . . any suggestions?

stupid · 02-16-08

the substring function is used like this:

string.SubString(int starting index, int length of substring)

Since you are trying to get the last 4 digits, you would need to use substring(12, 4) - you are trying to get a 15 character substring that is located afer position 12, which is obviously not there, hence the out of bounds error.

DanNEBTD · 02-16-08

Quote:

Originally Posted by stupid

the substring function is used like this:

string.SubString(int starting index, int length of substring)

Since you are trying to get the last 4 digits, you would need to use substring(12, 4) - you are trying to get a 15 character substring that is located afer position 12, which is obviously not there, hence the out of bounds error.

hehe, never actually had to use that in C++ so I never read up on it. Thanks for the help.