Objective C - Remove last character from string

Question

In Objective C for the iPhone, how would I remove the last character of a string using a button action.

Answer 1

The documentation is your friend, NSString supports a call substringWithRange that can shorten the string that you have an return the shortened String. You cannot modify an instance of NSString it is immutable. If you have an NSMutableString is has a method called deleteCharactersInRange that can modify the string in place

...
NSRange r;
r.location = 0;
r.size = [mutable length]-1;
NSString shorted = [stringValue substringWithRange:r];
...

Answer 2

In your controller class, create an action method you will hook the button up to in Interface Builder. Inside that method you can trim your string like this:

if ( [string length] > 0 )
    string = [string substringToIndex:[string length] - 1];

Answer 3

If it's an NSMutableString (which I would recommend since you're changing it dynamically), you can use:

[myString replaceCharactersInRange:NSMakeRange([myString length]-1, 1) withString:@""];