ios - How to fix warning: Incompatible pointer types assigning to 'NSMutableString *' from 'NSString *'

Question

I have this line of code that is giving me a warning:

result = [result substringToIndex:[result length] - 1];

The warning is:

Incompatible pointer types assigning to 'NSMutableString *' from 'NSString *'

I think I understand what the problem is (my use of the substring returns NSString?) - I just don't know how to fix it. Can someone please enlighten me?

Answer 1

result = [[result substringToIndex:[result length] - 1] mutableCopy]

假设结果是 NSMutableString 类。

Answer 2

在这里找到答案：

[result deleteCharactersInRange:NSMakeRange([result length]-1, 1)];

感谢您的努力；我很感激。标清