Question

Probably is a basic issue but I am trying to set an array objectAtIndex from another array and following gives an error. Thanks for help.

[self.appUrl objectAtIndex: 0] = [self.appCell objectAtIndex: 1];

Answer 1

NSArray’s are not mutable. If you want to change an object you can;

NSMutableArray *arrayCopy = [originalArray mutableCopy];
[arrayCopy replaceObjectAtIndex:0 withObject:newObject];
//assign the changed copy to the original variable name.
originalArray = arrayCopy;

So:

[self.appUrl objectAtIndex: 0] = [self.appCell objectAtIndex: 1];

Is:

NSMutableArray *copy = [self.appUrl mutableCopy];
[copy replaceObjectAtIndex:0 withObject:[self.appCell objectAtIndex:1]];
[self.appUrl mutableCopy];

Or simply declare your Array as mutable:

@property (nonatomic,retain) NSMutableArray *appUrl;