如何拷贝数组？

Question

我有四个数组，如下：

toArray = [[NSMutableArray alloc] initWithObjects:@"to 1",@"to 2",@"to 3",@"to 4",@"to 5",@"to 6",@"to 7",nil]; 
fromArray = [[NSMutableArray alloc] initWithObjects:@"from 1",@"from 2",@"from 3",@"from 4",@"from 5",@"from 6",@"from 7",nil]; 
messageArray = [[NSMutableArray alloc] initWithObjects:@"message 1",@"message 2",@"message 3",@"message 4",@"message 5",@"message 6",@"message 7",nil]; 
dayArray = [[NSMutableArray alloc] initWithObjects:@"day 1",@"day 2",@"day 3",@"day 4",@"day 5",@"day 6",@"day 7",nil];

我想复制或创建一个数组，它应该包含所有这4个数组。我怎样才能做到这一点？

Answer 1

你的问题有点模棱两可；你想要怎样的结果？

NSMutableArray *completeArray = [NSMutableArray array];
[completeArray addObjectsFromArray:toArray];
[completeArray addObjectsFromArray:fromArray];
[completeArray addObjectsFromArray:messageArray];
[completeArray addObjectsFromArray:dayArray];

或

NSMutableArray *completeArray  = [NSMutableArray arrayWithObjects:toArray, fromArray, messageArray, dayArray, nil];

或者如果所有数组都有相同数量的元素：

NSMutableArray *completeArray = [NSMutableArray array];
for (NSUInteger i = 0; i < [toArray count]; i++)
{
    NSString *fullString = [NSString stringWithFormat:@"%@ %@ %@ %@", [toArray objectAtIndex:i], [fromArray objectAtIndex:i], [messageArray objectAtIndex:i], [dayArray objectAtIndex:i]];
    [completeArray addObject:fullString];
}

或者，作为字典数组(也假设所有数组的长度相同)：

NSMutableArray *completeArray = [NSMutableArray array];
for (NSUInteger i = 0; i < [toArray count]; i++)
{
    NSDictionary *dict = [NSDictionary dictionaryWithObjectsAndKeys:
        [toArray objectAtIndex:i], @"to",
        [fromArray objectAtIndex:i], @"from",
        [messageArray objectAtIndex:i], @"message",
        [dayArray objectAtIndex:i], @"day",
        nil];
    [completeArray addObject:dict];
}

Answer 2

这应该是可行的：

NSArray *singleArray = [NSArray arrayWithElements:toArray, fromArray, messsageArray, dayArray, nil]; 
// mind the nil element at the end

Answer 3

NSMutableArray *result = [NSMutableArray arrayWithCapacity:0];

[result addObjectsFromArray:toArray];
[result addObjectsFromArray:fromArray];
[result addObjectsFromArray:messageArray];
[result addObjectsFromArray:dayArray];