Example of passing by reference in Objective-C

passbyreference

static void ChangeString(NSMutableString *theString) {
    [theString insertString:@"xyzabc" atIndex:3];
    NSLog(@"String inside ChangeString: %@", theString);
}

int main(int argc, const char * argv[])
{
    @autoreleasepool {
        NSMutableString *aString = [[NSMutableString alloc] initWithString:@"This is my string"];
        NSLog(@"String before ChangeString: %@", aString);
        ChangeString(aString);
        NSLog(@"String after ChangeString: %@", aString);
    }
    return 0;
}