1.sortedArrayUsingSelector
(按Key值大小对NSDictionary排序)
NSMutableArray *array = [NSMutableArray arrayWithObjects: [NSDictionary dictionaryWithObjectsAndKeys:@"Obj0", [NSNumber numberWithInt:0], nil], [NSDictionary dictionaryWithObjectsAndKeys:@"Obj5", [NSNumber numberWithInt:5], nil], [NSDictionary dictionaryWithObjectsAndKeys:@"Obj2", [NSNumber numberWithInt:2], nil], [NSDictionary dictionaryWithObjectsAndKeys:@"Obj3", [NSNumber numberWithInt:3], nil], [NSDictionary dictionaryWithObjectsAndKeys:@"Obj1", [NSNumber numberWithInt:1], nil], [NSDictionary dictionaryWithObjectsAndKeys:@"Obj4", [NSNumber numberWithInt:4], nil], nil]; NSArray *resultArray = [array sortedArrayUsingSelector:@selector(compare:)];
因为NSDictionary没有compare的排序比较方法,所以需要我们自己写
.h @interface NSDictionary (compare) {} -(NSComparisonResult)compare:(NSDictionary *)otherDictionary; @end .m @implementation NSDictionary (compare) - (NSComparisonResult)compare: (NSDictionary *)otherDictionary { NSDictionary *tempDictionary = (NSDictionary *)self; NSNumber *number1 = [[tempDictionary allKeys] objectAtIndex:0]; NSNumber *number2 = [[otherDictionary allKeys] objectAtIndex:0]; NSComparisonResult result = [number1 compare:number2]; return result == NSOrderedDescending; // 升序 // return result == NSOrderedAscending; // 降序 } @end
2.sortedArrayUsingComparator
NSMutableArray *array = [NSMutableArray arrayWithObjects: [NSDictionary dictionaryWithObjectsAndKeys:@"Obj0", [NSNumber numberWithInt:0], nil], [NSDictionary dictionaryWithObjectsAndKeys:@"Obj5", [NSNumber numberWithInt:5], nil], [NSDictionary dictionaryWithObjectsAndKeys:@"Obj2", [NSNumber numberWithInt:2], nil], [NSDictionary dictionaryWithObjectsAndKeys:@"Obj3", [NSNumber numberWithInt:3], nil], [NSDictionary dictionaryWithObjectsAndKeys:@"Obj1", [NSNumber numberWithInt:1], nil], [NSDictionary dictionaryWithObjectsAndKeys:@"Obj4", [NSNumber numberWithInt:4], nil], nil]; // NSArray *resultArray = [array sortedArrayUsingSelector:@selector(compare:)]; NSArray *resultArray = [array sortedArrayUsingComparator:^NSComparisonResult(id obj1, id obj2) { NSNumber *number1 = [[obj1 allKeys] objectAtIndex:0]; NSNumber *number2 = [[obj2 allKeys] objectAtIndex:0]; NSComparisonResult result = [number1 compare:number2]; return result == NSOrderedDescending; // 升序 // return result == NSOrderedAscending; // 降序 }];
3.sortedArrayUsingDescriptors & sortUsingDescriptors
前者带返回值,是NSArray的方法,排好序的数组是返回值中的数组;
后者不带返回值,是NSMutableArray的方法,是对当前数组自己排序
.h @interface Person : NSObject { NSString *_name; NSInteger _age; } @property (nonatomic, retain) NSString *name; @property (nonatomic, assign) NSInteger age; @end .m @implementation Person @synthesize name = _name; @synthesize age = _age; - (void)dealloc { [_name release]; [super dealloc]; } @end
Person *person1 = [[Person alloc] init]; [person1 setName:@"ABC"]; [person1 setAge:24]; Person *person2 = [[Person alloc] init]; [person2 setName:@"ACB"]; [person2 setAge:22]; Person *person3 = [[Person alloc] init]; [person3 setName:@"ABD"]; [person3 setAge:33]; NSMutableArray *array = [NSMutableArray arrayWithObjects:person1, person2, person3, nil]; [person1 release]; [person2 release]; [person3 release]; NSSortDescriptor *sortDescriptor = [NSSortDescriptor sortDescriptorWithKey:@"_age" ascending:YES]; NSArray *tempArray = [array sortedArrayUsingDescriptors:[NSArray arrayWithObject:sortDescriptor]]; for(NSInteger i = 0; i < [tempArray count]; i++) { NSLog(@"%@--------%d\n", [[tempArray objectAtIndex:i] name], [[tempArray objectAtIndex:i] age]); } // [array sortUsingDescriptors:[NSArray arrayWithObject:sortDescriptor]]; // // for(NSInteger i = 0; i < [array count]; i++) // { // NSLog(@"%@--------%d\n", [[array objectAtIndex:i] name], [[array objectAtIndex:i] age]); // }
sortDescriptorWithKey:@"_age",以age作为标准来做比较。
Person *person1 = [[Person alloc] init]; [person1 setName:@"ABCD"]; [person1 setAge:24]; Person *person2 = [[Person alloc] init]; [person2 setName:@"ACBD"]; [person2 setAge:22]; Person *person3 = [[Person alloc] init]; [person3 setName:@"ABDC"]; [person3 setAge:33]; Person *person4 = [[Person alloc] init]; [person4 setName:@"ACDB"]; [person4 setAge:22]; NSMutableArray *array = [NSMutableArray arrayWithObjects:person1, person3, person4, person2, nil]; [person1 release]; [person2 release]; [person3 release]; [person4 release]; NSSortDescriptor *sortDescriptor1 = [NSSortDescriptor sortDescriptorWithKey:@"_age" ascending:YES]; NSSortDescriptor *sortDescriptor2 = [NSSortDescriptor sortDescriptorWithKey:@"_name" ascending:YES]; NSArray *tempArray = [array sortedArrayUsingDescriptors:[NSArray arrayWithObjects:sortDescriptor1, sortDescriptor2, nil]]; for(NSInteger i = 0; i < [tempArray count]; i++) { NSLog(@"%@--------%d\n", [[tempArray objectAtIndex:i] name], [[tempArray objectAtIndex:i] age]); } // [array sortUsingDescriptors:[NSArray arrayWithObject:sortDescriptor]]; // // for(NSInteger i = 0; i < [array count]; i++) // { // NSLog(@"%@--------%d\n", [[array objectAtIndex:i] name], [[array objectAtIndex:i] age]); // }
NSSortDescriptor *sortDescriptor1 = [NSSortDescriptorsortDescriptorWithKey:@"_age"ascending:YES];
NSSortDescriptor *sortDescriptor2 = [NSSortDescriptorsortDescriptorWithKey:@"_name"ascending:YES];
NSArray *tempArray = [array sortedArrayUsingDescriptors:[NSArrayarrayWithObjects:sortDescriptor1, sortDescriptor2,
nil]];
这里的NSArray中的第一元素表示首先按照这个元素的升序或者降序进行排序,对于有重复项的,再按照第二元素进行排序,依次进行类推