iOS---数组那些事儿

1、对数组中的元素排序：

     NSMutableArray *arr = [NSMutableArray arrayWithObjects:@"0",@"8",@"6",@"1",nil];
     NSArray *sortedArray = [arr sortedArrayUsingComparator:^NSComparisonResult(id obj1, id obj2){
if ([obj1 intValue] > [obj2 intValue]){
return NSOrderedDescending;//降序
}
if ([obj1 intValue] < [obj2 intValue]){
return NSOrderedAscending;//升序
}
return NSOrderedSame;
}];
      NSLog(@"排序后的数组：%@",sortedArray);

2、数组与数组的包含关系
NSArray *Arrs1 = @[@"1",@"2",@"3",@"4",@"5"];  
NSArray *Arrs2 = @[@"1",@"2"];    
    BOOL isContains = YES;  
  for (NSString *a in Arrs2) {    
    if (![Arrs1 containsObject:a]) {        
    isContains = NO;   
     }   
 }   
 NSLog(@"%@",isContains?@"包含":@"不包含");

3、数组与元素的包含关系
    NSString *str = @"数组";
    NSArray *array=@[@"who",@"数组",@"array",@"3"];
    BOOL isbool = [array containsObject: str];
    NSLog(@"%i",isbool);