Question

创建包含另一个数组的某些元素的数组的方法是什么？我有代码：

NSArray *columnArray = @[@"o", @"o", @"o", @"o", @"o", @"o", @"o", @"o", @"o", @"o"];
NSMutableArray *board = [[NSMutableArray alloc] initWithCapacity:10];

for (int columnIndex = 0; columnIndex < 10; columnIndex ++)
{
    [board addObject:[columnArray mutableCopy]];
}

for (int i=0; i<4; i++) 
{
    int column1 = arc4random() % 10;//column
    int row1 = arc4random() % 10;//row

    if ([[[board objectAtIndex:column1] objectAtIndex: row1 ] isEqualToString:@"X" ])
    {
        column1=arc4random() %10;
        row1=arc4random() %10;                
    }

    [[board objectAtIndex:row1] replaceObjectAtIndex:column1   withObject:@"X"];            
}

如何将“X”的所有元素放在另一个数组中？

Answer 1

NSPredicate和filteredArrayUsingPredicate：非常简单易用：

NSPredicate *predicate = [NSPredicate predicateWithBlock:^BOOL(NSString *object, NSDictionary *bind){
    return // your test here, evaluating to a BOOL
}];

NSArray *found = [myArray filteredArrayUsingPredicate:predicate];

使用另一个数组的可用元素创建数组

1 个答案: