当这本书开始讨论使用sort
andcompareNames:
方法对数组中的元素进行字母排序时,我有些困惑。compareNames
调用方法时如何获取参数sort
?当所有返回的都是 类型时,元素实际上是如何按字母顺序排列的NSComparisonResult
?
#import <Foundation/Foundation.h>
@interface AddressCard : NSObject
@property (copy, nonatomic) NSString *name, *email;
-(NSComparisonResult) compareNames: (id) element;
@end
@implementation AddressCard
@synthesize name, email;
-(NSComparisonResult) compareNames:(id)element {
return [name compare: [element name]];
}
@end
#import "AddressCard.h"
#import <Foundation/Foundation.h>
@interface AddressBook : NSObject
@property (nonatomic, copy) NSString *bookName;
@property (nonatomic, strong) NSMutableArray *book;
-(void) addCard: (AddressCard *) myCard;
-(void) sort;
@end
@implementation AddressBook
@synthesize book, bookName;
-(void) sort {
[book sortUsingSelector: @selector(compareNames:)];
}