Is it necessary to assign a string to a variable before comparing it to another?

I want to compare the value of an NSString to the string "Wrong". Here is my code:

NSString *wrongTxt = [[NSString alloc] initWithFormat:@"Wrong"];
if( [statusString isEqualToString:wrongTxt] ){
     doSomething;
}

Do I really have to create an NSString for "Wrong"?

Also, can I compare the value of a UILabel's text to a string without assigning the label value to a string?

> Do I really have to create an NSString for "Wrong"?

No, why not just do:

if([statusString isEqualToString:@"Wrong"]){
    //doSomething;
}

Using @"" simply creates a string literal, which is a valid NSString.

> Also, can I compare the value of a UILabel.text to a string without assigning the label value to a string?

Yes, you can do something like:

UILabel *label = ...;
if([someString isEqualToString:label.text]) {
    // Do stuff here 
}

if ([statusString isEqualToString:@"Wrong"]) {
    // do something
}

Brian, also worth throwing in here - the others are of course correct that you don't need to declare a string variable. However, next time you want to declare a string you don't need to do the following:

NSString *myString = [[NSString alloc] initWithFormat:@"SomeText"];

Although the above does work, it provides a retained NSString variable which you will then need to explicitly release after you've finished using it.

Next time you want a string variable you can use the "@" symbol in a much more convenient way:

NSString *myString = @"SomeText";

This will be autoreleased when you've finished with it so you'll avoid memory leaks too...

Hope that helps!

You can also use the NSString class methods which will also create an autoreleased instance and have more options like string formatting:

NSString *myString = [NSString stringWithString:@"abc"];
NSString *myString = [NSString stringWithFormat:@"abc %d efg", 42];