iOS简单排序--字母排序、NSDictionary排序

//数组用系统方法compare做字母的简单排序

   NSArray
*oldArray = @[@"bac",@"bzd",@"azc",@"azz"];
  NSArray *newArray = [oldArray
sortedArrayUsingSelector:@selector(compare:)];

   NSLog(@"new array = %@",newArray);

    
//因为NSDictionary排序

   NSMutableDictionary
*dict = [[NSMutableDictionary alloc]init];
    [dict
setObject:@"1"
forKey:@"key1"];
    [dict
setObject:@"2"
forKey:@"key2"];
    [dict
setObject:@"3"
forKey:@"key3"];
    [dict
setObject:@"4"
forKey:@"key4"];

    
   for (NSString *str
in [dict allKeys]) {
      NSLog(@"key ==%@",str);
    }

    
   NSArray *keys = [dict
allKeys];
   NSArray *sortedArray = [keys
sortedArrayUsingComparator:^NSComparisonResult(id obj1,
id obj2){

      
return [obj1 compare:obj2 options:NSNumericSearch];
    }];

    
   for (NSString *categoryId
in sortedArray) {

      
NSLog(@"[dict objectForKey:categoryId] ===%@",[dict
objectForKey:categoryId]);
    }