iphone - 从具有给定索引的字符串中获取子字符串

Question

我正在尝试从字符串中获取 SubString

这是我正在调用的方法

-(NSString *)subStringBetweenStrings:(NSString*)str open:(NSString*)open close:(NSString *)close
{
    if ( str == nil || open == nil || close == nil )
        return nil;

    int start = [str rangeOfString:open].location;
    if (start != -1)
    {
        int end = [str rangeOfString:close].location;
        if ( end != -1)
        {
            return [str substringFromIndex:start]; // DONT WANT
        }
    }
    return nil;       
}

我有start point，我有End point。如何从开始和结束索引中获取子字符串，例如 return[ str subStringWithRange:(start, end)];

Answer 1

挑剔...

• 替换int start为NSUInteger，NSRange location就是这样定义的，
• 不要比较start，-1而是要NSNotFound

... 回答 ...

return [str substringWithRange:NSMakeRange( start, end - start + 1 )]