ios - 排序字符串包含数字，NSMutableArray 与字典

Question

字符串如

"4 Miles 400 stones"
"2 Miles 10 stones"
"6 Miles 2 Stones" 

NsMutableArray 中字典的键值，我试图按英里数然后按石头对它们进行排序。

常规sortUsingDescriptor:

[list sortUsingDescriptors:[NSArray arrayWithObjects:[NSSortDescriptor sortDescriptorWithKey:@"systems"升序:YES], nil]];

或NSNumericSearch:

NSMutableArray *newList;
        NSArray *result = [list sortedArrayUsingFunction:&sort context:@"systems"];
        newList= [[NSMutableArray alloc] initWithArray:result];

NSInteger sort(id a, id b, void* p) {
    return [[a valueForKey:(__bridge NSString*)p]
            compare:[b valueForKey:(__bridge NSString*)p]
            options:NSNumericSearch];
}

不工作。

我是否必须解析字符串并获取数字然后对其进行排序？或者有更简单的方法来对此进行排序吗？

Answer 1

这是最好的、面向对象的方法。

首先。创建一个类。我们将其命名为 MyObject:

@interface MyObject : NSObject
@property(nonatomic, assign) NSUInteger miles;
@property(nonatomic, assign) NSUInteger stones;

+ (MyObject *)objectWithString:(NSString *)string;

@end

如您所见，它有一个 objectWithString，我们将使用它来使用字符串中的信息创建对象，例如:“4 Miles 400stones”。

@implementation MyObject

+ (MyObject *)objectWithString:(NSString *)string
{
    NSRegularExpression *regex = [NSRegularExpression regularExpressionWithPattern:@"[0-9]+?(?= Miles | stones)" options:0 error:nil];
    NSArray *matches = [regex matchesInString:string options:0 range:NSMakeRange(0, [string length])];

    MyObject *myObject = [[MyObject alloc] init];

    myObject.miles = [[string substringWithRange:((NSTextCheckingResult *)matches[0]).range] integerValue];
    myObject.stones = [[string substringWithRange:((NSTextCheckingResult *)matches[1]).range] integerValue];

    return myObject;
}

- (NSString *)description
{
    return [NSString stringWithFormat:@"%d miles, %d stones", self.miles, self.stones];
}

@end

然后，我们将使用 NSSortDescriptor 对我们的数组进行排序:

MyObject *myObject1 = [MyObject objectWithString:@"4 Miles 400 stones"];
MyObject *myObject2 = [MyObject objectWithString:@"2 Miles 10 stones"];
MyObject *myObject3 = [MyObject objectWithString:@"6 Miles 2 stones"];

NSArray *array = @[myObject1, myObject2, myObject3];

NSSortDescriptor *miles = [[NSSortDescriptor alloc] initWithKey:@"miles" ascending:YES];
NSSortDescriptor *stones = [[NSSortDescriptor alloc] initWithKey:@"stones" ascending:YES];
NSArray *sortDescriptors = @[miles, stones];

NSArray *sortedArray = [array sortedArrayUsingDescriptors:sortDescriptors];

NSLog(@"Sorted: %@", sortedArray);

输出:

2014-03-05 19:51:54.233 demo[12267:70b] Sorted: (
    "2 miles, 10 stones",
    "4 miles, 400 stones",
    "6 miles, 2 stones" )

它就像一个魅力，我的 friend !