CODEWITHSUNDEEP
iphoneobjective-cnsstringnsmutablestring
darksky
darksky

Reputation: 21019

NSMutableString Append Fails

I have an NSString that I'd like to append a { at the beginning of it.

 NSMutableString *str = [[NSMutableString alloc] initWithString:@"{"];
    [str stringByAppendingString:extracted];

This returns str with only {. Why is that? Objective-C is VERY frustrating with how it provides many ways of doing the same thing, yet for situations a different way is required.

I tried doing [NSMutableString string] and appending { then extracted and it still does not work. Why is this not working and what should I do?

Upvotes: 0

Views: 204

Answers (3)

Abhishek
Abhishek

Reputation: 2253

// use it like this

NSString *extracted = @"this is my string";
NSString *str = [[NSString alloc] initWithString:@"{"];
str =  [str stringByAppendingString:extracted];

Hope this will help you

Upvotes: 1

Hampus Nilsson
Hampus Nilsson

Reputation: 6822

stringByAppendingString returns a new string, it does not modify the old string.

All functions that begins with stringWith or arrayWith etc. create new objects rather than modifying old objects.

To acheive what you want, a simpler solution is:

 NSString *str = [NSString stringWithFormat:@"{%@", oldString];

or:

 NSMutableString *str = [@"{" mutableCopy];
 [str appendString:blah];

Upvotes: 6

Joe
Joe

Reputation: 57169

You are calling an NSString method that returns a new string and does not modify the string that it is called on. You need to call appendString.

[str appendString:extracted];

Upvotes: 5

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