CODEWITHSUNDEEP
objective-cnsstring
objective_c_pro
objective_c_pro

Reputation: 925

How to append a NSString onto another NSString

I am relatively new in Objective C but not with programming. I was wondering how you can append one NSString onto another. I am making an app in which a user has to finish a basic sentence, and I was wondering how to get the string the user entered and append it onto the current one that is on the screen?

Upvotes: 29

Views: 54903

Answers (4)

Fogh
Fogh

Reputation: 1305

This could also be achieved by using a NSMutableString:

NSMutableString *string = [NSMutableString stringWithString:@"String 1"];
[string appendString:@"String 2"];

Upvotes: 42

John Bowers
John Bowers

Reputation: 1795

You cannot truly append one NSString to another because the class NSString is not mutable. All of the standard data structures have mutable and non mutable varieties (NSMutableString vs NSString, NSMutableArray vs NSArray, etc). If you want to change the contents without reallocating a new object, you will want to use the mutable version. You can recreate a new NSString using:

NSString* string3 = [NSString stringWithFormat:@"%@%@",string1,string2];

This is bad for performance though, so if you are going to do it in a loop or some performance sensitive area (i.e. you keep appending to the same string over and over again) this is guaranteed to cause you a problem (I have made this mistake before).

Instead you probably should use the NSMutableString and append the second string to it:

NSMutableString* string1 = [NSMutableString alloc] init];
[string1 appendString:string2];

Upvotes: 6

Imirak
Imirak

Reputation: 1333

It looks like you have your answer but you can also use the stringWithFormat: method like so:

NSString *sample1 = @"Hello"; 
NSString *sample2 = @"Being appended";

NSString *complete = [NSString stringWithFormat:@"%@%@", sample1,
sample2];

Upvotes: 14

Ankit
Ankit

Reputation: 1694

I think you are looking for stringByAppendingString function of NSString. See the example below.

NSString *errorTag = @"Error: ";
NSString *errorString = @"premature end of file.";
NSString *errorMessage = [errorTag stringByAppendingString:errorString];

produces the string “Error: premature end of file.”.

Upvotes: 50

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