Question

when i am using string concatenation in method(like -(IBAction)buttonDigitPressed:(id)sender) it shows the blank.I am recall the method automatically terminate the app. what is the problem plz replay me.

NSString *str= @"";

-(IBAction)buttonDigitPressed:(id)sender{

    int a = (int)[sender tag];
    str= [str stringByAppendingFormat:@"%i",a];
    label1.text= str;
}

this is the code. check the code send me the replay where i am doing the mistake.

Answer 1

str in the method is an autoreleased object. Make it a copy property and do

self.str = [self.str stringByAppendingFormat:@"%i",a];
label1.text = self.str;

If str is same as label1.text then do this directly.

label1.text = [label1.text stringByAppendingFormat:@"%i",a];