用第二个词排序nsarray。 （由姓氏在“姓氏姓氏”中的一种字符串数组）

Question

我正在使用像“姓氏姓氏”这样的字符串。现在我想用第二个词，即姓氏来排序那个字符串数组。 我用过这个方法

NSArray *sortedArray=[[teachersList allValues] sortedArrayUsingSelector:@selector(localizedCaseInsensitiveCompare:)];
    NSLog(@"After %@",sortedArray);

但它在第一个单词上排序数组。

我也有字符的元素或字符串只表示第一个单词。

那怎么办呢？

修改

@Janak Nirmal

我的修改后的代码是：

while([resultSet next])
{
    [teachersList setObject:[NSString stringWithFormat:@"%@ %@",[resultSet stringForColumn:@"first_name"],[resultSet stringForColumn:@"last_name"]] forKey:[resultSet stringForColumn:@"email_id"]];
    [emailList addObject:[resultSet stringForColumn:@"email_id"]];
    appDelegate.grade=[resultSet stringForColumn:@"grade"];

}

    //NSArray *sortedArrays=[[teachersList allValues] sortedArrayUsingSelector:@selector(localizedCaseInsensitiveCompare:)];


   NSArray *sortedArray = [[teachersList allValues] sortedArrayUsingComparator:^NSComparisonResult(id a, id b) {
        NSString *firstTeacher2ndWord = [[[[(Teacher*)a name] componentsSeparatedByString:@" "] objectAtIndex:1] lowercaseString];
        NSString *secondTeacher2ndWord = [[[[(Teacher*)b name] componentsSeparatedByString:@" "] objectAtIndex:1] lowercaseString];
        return [firstTeacher2ndWord compare:secondTeacher2ndWord];
    }];

但我收到了以下错误

[__ NSCFString name]：发送到实例的无法识别的选择器

Answer 1

你可以这样做，

NSArray *sortedArray = [teacherList sortedArrayUsingComparator:^NSComparisonResult(id a, id b) {
    NSString *firstTeacher2ndWord = [[[[(Teacher*)a name] componentsSeparatedByString:@" "] objectAtIndex:1] lowercaseString];
    NSString *secondTeacher2ndWord = [[[[(Teacher*)b name] componentsSeparatedByString:@" "] objectAtIndex:1] lowercaseString];
    return [firstTeacher2ndWord compare:secondTeacher2ndWord];
}];
//Assuming in above you have atleast 2 words in name 
//i.e. objectAtIndex:1 doesn't fail or you need to put condition 
//there according to your needs

假设您的模型结构如下，

@interface Teacher : NSObject

@property (nonatomic,strong) NSString *name;

@end

修改

由于您的[teacherList allValues]将直接保存字符串值，您应该按如下所示编写

NSArray *sortedArray = [[teachersList allValues] sortedArrayUsingComparator:^NSComparisonResult(id a, id b) {
    NSString *firstTeacher2ndWord = [[[((NSString*)a) componentsSeparatedByString:@" "] objectAtIndex:1] lowercaseString];
    NSString *secondTeacher2ndWord = [[[((NSString*)b) componentsSeparatedByString:@" "] objectAtIndex:1] lowercaseString];
    return [firstTeacher2ndWord compare:secondTeacher2ndWord];
}];

上面的代码将直接以排序的方式为您提供所有值的数组。

Answer 2

因为您有单个字符串，它将始终从“first name”

开始比较

  

所以你必须先按空格分割字符串

NSArray *listItems = [list componentsSeparatedByString:@" "];

从这里开始，您必须使用此分割字符串（如

）构建名称字典

@{@"FirstName" : listItems[0], "FirstName" : listItems[1]}

和add into array and then you can sort这个

NSArray *keys = [theDictionary allKeys];
NSArray *sortedKeys = [keys sortedArrayUsingSelector:@selector(compareMethod:)];