Question

I want to construct a string with an array of objects

for (int n=0; n<[friends count]; n++) {
    User* friend = [friends objectAtIndex:n];
    if (n>=[friends count]-1) {
        NSString* param = [NSString stringWithFormat:@"{\"target_id\":\"dummy(%d)\"}", [friend uid]];
        NSString* sf2 = [[NSString alloc]init];
        sf2= [sf stringByAppendingString:param];
        [sf release];
        sf = [[NSString alloc]initWithString:sf2];
        [sf2 release];
        [param release];
    }else{
        NSString* param = [NSString stringWithFormat:@"{\"target_id\":\"dummy(%d)\"},", [friend uid]];

        NSString* sf2 = [[NSString alloc]init];
        sf2= [sf stringByAppendingString:param];
        [sf release];
        sf = [[NSString alloc]initWithString:sf2];
        [sf2 release];
        [param release];
    }

}

I want to know what I’m doing wrong.
Thanks in advance!!

Answer 1

param is autoreleased object so you should not release it.

Edit:
//initialize sf here.

for (int n=0; n<[friends count]; n++) {
    User* friend = [friends objectAtIndex:n];
    if (n>=[friends count]-1) {
        NSString* param = [NSString stringWithFormat:@"{\"target_id\":\"dummy(%d)\"}", [friend uid]];
        sf = [sf stringByAppendingString:param];
    }else{
        NSString* param = [NSString stringWithFormat:@"{\"target_id\":\"dummy(%d)\"},", [friend uid]];

        sf = [sf stringByAppendingString:param];
    }

}