如何排序一个NSArray字母?

如何将一个数组填充为[UIFont familyNames]按字母顺序排序?

223912 次浏览
小开
最佳答案

最简单的方法是，提供一个排序选择器(详细信息为苹果公司的文档)

objective - c

sortedArray = [anArray sortedArrayUsingSelector:@selector(localizedCaseInsensitiveCompare:)];

斯威夫特

let descriptor: NSSortDescriptor = NSSortDescriptor(key: "YourKey", ascending: true, selector: "localizedCaseInsensitiveCompare:")
let sortedResults: NSArray = temparray.sortedArrayUsingDescriptors([descriptor])

Apple为字母排序提供了几个选择器:

  • compare:
  • caseInsensitiveCompare:
  • localizedCompare:
  • localizedCaseInsensitiveCompare:
  • localizedStandardCompare:

斯威夫特

var students = ["Kofi", "Abena", "Peter", "Kweku", "Akosua"]
students.sort()
print(students)
// Prints "["Abena", "Akosua", "Kofi", "Kweku", "Peter"]"

Reference .

小开

这里提供的其他答案提到使用@selector(localizedCaseInsensitiveCompare:) 这对于NSString数组非常有用，但是如果你想将它扩展到另一种类型的对象，并根据'name'属性对这些对象进行排序，你应该这样做:

NSSortDescriptor *sort = [NSSortDescriptor sortDescriptorWithKey:@"name" ascending:YES];
sortedArray=[anArray sortedArrayUsingDescriptors:@[sort]];

您的对象将根据这些对象的name属性进行排序。

如果希望排序不区分大小写，则需要像这样设置描述符

NSSortDescriptor *sort = [NSSortDescriptor sortDescriptorWithKey:@"name" ascending:YES selector:@selector(caseInsensitiveCompare:)];
小开

一个更强大的排序NSString列表的方法是使用NSNumericSearch:

NSArray *sortedArrayOfString = [arrayOfString sortedArrayUsingComparator:^NSComparisonResult(id obj1, id obj2) {
return [(NSString *)obj1 compare:(NSString *)obj2 options:NSNumericSearch];
}];

结合SortDescriptor，它会给出如下内容:

NSSortDescriptor *sort = [NSSortDescriptor sortDescriptorWithKey:@"name" ascending:YES comparator:^NSComparisonResult(id obj1, id obj2) {
return [(NSString *)obj1 compare:(NSString *)obj2 options:NSNumericSearch];
}];
NSArray *sortedArray = [anArray sortedArrayUsingDescriptors:[NSArray arrayWithObject:sort]];
小开 
-(IBAction)SegmentbtnCLK:(id)sender
{ [self sortArryofDictionary];
[self.objtable reloadData];}
-(void)sortArryofDictionary
{ NSSortDescriptor *sorter;
switch (sortcontrol.selectedSegmentIndex)
{case 0:
sorter=[[NSSortDescriptor alloc]initWithKey:@"Name" ascending:YES];
break;
case 1:
sorter=[[NSSortDescriptor alloc]initWithKey:@"Age" ascending:YES];
default:
break; }
NSArray *sortdiscriptor=[[NSArray alloc]initWithObjects:sorter, nil];
[arr sortUsingDescriptors:sortdiscriptor];
}
小开

使用以下代码按字母顺序排序:

    NSArray *unsortedStrings = @[@"Verdana", @"MS San Serif", @"Times New Roman",@"Chalkduster",@"Impact"];


NSArray *sortedStrings =
[unsortedStrings sortedArrayUsingSelector:@selector(compare:)];


NSLog(@"Unsorted Array : %@",unsortedStrings);
NSLog(@"Sorted Array : %@",sortedStrings);

下面是控制台日志:

2015-04-02 16:17:50.614 ToDoList[2133:100512] Unsorted Array : (
Verdana,
"MS San Serif",
"Times New Roman",
Chalkduster,
Impact
)


2015-04-02 16:17:50.615 ToDoList[2133:100512] Sorted Array : (
Chalkduster,
Impact,
"MS San Serif",
"Times New Roman",
Verdana
)
小开

另一个简单的方法是使用NSString description属性对字符串数组进行排序:

NSSortDescriptor *valueDescriptor = [NSSortDescriptor sortDescriptorWithKey:@"description" ascending:YES];
arrayOfSortedStrings = [arrayOfNotSortedStrings sortedArrayUsingDescriptors:@[valueDescriptor]];
小开

对于大多数目的，这已经有了很好的答案，但我将添加我的更具体的答案。

在英语中，通常我们按字母顺序排列时，会忽略短语开头的单词“the”。所以“United States”应该在“U”下面，而不是“T”下面。

这个可以帮你。

最好把这些分类。

// Sort an array of NSStrings alphabetically, ignoring the word "the" at the beginning of a string.


-(NSArray*) sortArrayAlphabeticallyIgnoringThes:(NSArray*) unsortedArray {


NSArray * sortedArray = [unsortedArray sortedArrayUsingComparator:^NSComparisonResult(NSString* a, NSString* b) {


//find the strings that will actually be compared for alphabetical ordering
NSString* firstStringToCompare = [self stringByRemovingPrecedingThe:a];
NSString* secondStringToCompare = [self stringByRemovingPrecedingThe:b];


return [firstStringToCompare compare:secondStringToCompare];
}];
return sortedArray;
}


// Remove "the"s, also removes preceding white spaces that are left as a result. Assumes no preceding whitespaces to start with. nb: Trailing white spaces will be deleted too.


-(NSString*) stringByRemovingPrecedingThe:(NSString*) originalString {
NSString* result;
if ([[originalString substringToIndex:3].lowercaseString isEqualToString:@"the"]) {
result = [[originalString substringFromIndex:3] stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceCharacterSet]];
}
else {
result = originalString;
}
return result;
}

提交答案