Question

This is the first time I’ve used a for loop in iOS! Hurrah!

Please note that “bookTitle” is an NSString object within the class. When this class initiates it takes a String argument and sets bookTitle to that.

books = [[NSMutableArray alloc] initWithObjects:

[[Book alloc] initWithTitle:@"What a great title" andAuthor:@"R Crimson"], 

[[Book alloc] initWithTitle:@"What another great title" andAuthor:@"R Crimson"], 
 nil ];
NSUInteger count = [books count];
for(NSUInteger i= 0; i < count;i++){
    Book *tb= [books objectAtIndex:i];
    if(tb.title=bookTitle){
        nameLabel.text=tb.title;
    }

Sadly both tb.title and bookTitle are null. What should happen is that any object in the array that has a title that matches bookTitle should then have its title assigned to the nameLabel.

So I’m wondering where I’ve gone wrong, and also if there’s a better solution? Because the title attribute isn’t a unique identifier, so if I add two objects with the same title to books (unlikely that I ever would, but still!) it’ll then return multiple objects, which is no good.

Thanks in advance.

Answer 1

You have an error in your if statement.

if (tb.title = bookTitle)

You only have one = in there, so you keep setting tb.title to bookTitle all the time.

But, instead of adding another equal sign, do this:

if ([tb.title isEqualToString:bookTitle]) {
    ...
}

More information here.