如何确定Objective C中的字符串是否相等？

Question

我从JSON结果中读取了一个字符串,如下所示:

NSString *strResult = [[NSString alloc] initWithBytes:[data bytes] 
                                               length:[data length] 
                                             encoding:NSUTF8StringEncoding]; 

然后我尝试确定字符串是否等于值"N"

if ([strResult isEqualToString:@"N"])
{ 
  [lblImageOK setHidden:YES]; 
} 
else 
{ 
  [lblImageOk setHidden:NO]; 
}

if语句allways返回else部分,即使结果为"N".它们都具有相同的值,但语句始终返回false.

Answer 1

我找到了清理字符串的方法,然后检查它们是否相等.

NSString *strResult = [[NSString alloc] initWithBytes:[data bytes] 
                                           length:[data length] 
                                         encoding:NSUTF8StringEncoding]; 

strResult = [strResult stringByReplacingOccurrencesOfString:@"\"" withString:@""];
strResult = [strResult stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceCharacterSet]];

if ([strResult isEqualToString:@"N"])
{ 
  [lblImageOK setHidden:YES]; 
} 
else 
{ 
  [lblImageOk setHidden:NO]; 
}