Array中对象的排序

1.子母排序

NSArray *kArrSort = [_dic allKeys]; //这里是字母数组:,g,a,b.y,m……

NSArray *resultkArrSort = [kArrSort sortedArrayUsingComparator:^NSComparisonResult(id obj1, id obj2) {

                                       return [obj1 compare:obj2   options:NSNumericSearch];

                                        }];

NSLog(@"%@",resultkArrSort);

2.数值排序

// sortedArrayUsingComparator:方法并不会改变array数组内部的顺序

NSArray *sortedArray = [array sortedArrayUsingComparator:^NSComparisonResult(NSNumber *obj1, NSNumber *obj2) {

                                    if ([obj1 intValue] < [obj2 intValue]) {

                                         return NSOrderedDescending;

                                   } else {

                                        return NSOrderedAscending;

                                 } }];

NSLog(@"%@", sortedArray);

3.使用NSDescriptor进行排序

我们将要排序的对象是一个Persion类，如下定义：

@interface Person : NSObject
@property (nonatomic, copy) NSString *name;
@property (nonatomic, copy) NSString *surname;
@property (nonatomic, strong) NSDate *dateOfBirth;
@end

而数组中包含如下内容：

Smith John 03/01/1984
Andersen Jane 16/03/1979
Clark Anne 13/09/1995
Smith David 19/07/1981
Johnson Rose 22/02/1989

NSSortDescriptor *firstDescriptor = [[NSSortDescriptor alloc] initWithKey:@"surname" ascending:YES];
NSSortDescriptor *secondDescriptor = [[NSSortDescriptor alloc] initWithKey:@"name" ascending:YES];

NSArray *sortDescriptors = [NSArray arrayWithObjects:firstDescriptor, secondDescriptor, nil];

NSArray *sortedArray = [self.persons sortedArrayUsingDescriptors:sortDescriptors];

上面代码的排序结果如下所示：

Andersen Jane
Clark Anne
Johnson Rose
Smith David
Smith John