如何将char数组的一部分转换为NSString *？

Question

char arr[] = "abcdefg";
// I know I can do this
NSString *s = [[NSString alloc] initWithCString:arr encoding:NSUTF8StringEncoding];

如果我想将部分arr数组转换为NSString *？说cde而不是整个字符串abcdefg？我如何实现这一目标？

Answer 1

NSString *s = [[NSString alloc] initWithBytes:arr + 2
    length:3 encoding:NSUTF8StringEncoding];