解决方法
不清楚你是否只想打印增量字符或全部.如果是前者,这是你将如何做到这一点：
NSString *myString = @"myString";
NSMutableString *newString = [NSMutableString string];
for (int i = 0; i < [myString length]; i++)
{
int ascii = [myString characterAtIndex:i];
if (i % 3 == 0)
{
ascii++;
[newString appendFormat:@"%c",ascii];
}
}
myLabel.text = newString;