可变数组的二维NSMutableArray，但不知道我需要多少 [英] Two-dimensional NSMutableArray of mutable arrays, but don't know how many I'll need

问题描述

我有一个大数组（几百个对象），我需要根据对象中的整数将其分成几个数组，但是我不知道我需要多少个数组。我以为使用二维NSMutableArray是可以的，但是如果我按如下所示进行操作，那么当我清空tempArray时，它也会清空fullArray中的数组。还有另一种使用临时可重复使用的数组的方法，一旦将其添加到另一个数组中，它就会释放对其的引用。

I have a large array (a few hundred objects), and I need to separate it into several arrays depending on an integer in the object, but I don't know how many arrays I'll need. I thought using a two-dimensional NSMutableArray would work, but if I do it as seen below, then when I empty the tempArray, it empties the array in fullArray as well. Is there another way to use a temporary, reusable array that, once it's been added to another array, it releases references to it.

- (void)createArray{

fullArray=[[NSMutableArray alloc]init];
NSMutableArray *tempArray=[[NSMutableArray alloc] init];

for(int j=0; j<numberOfGames; j++){

    for(int i=0; i<[appDelegate.hiddenChars count]; i++){
        Chars *charObj=[appDelegate.hiddenChars objectAtIndex:i];
        if(charObj.gameID==j){
            //NSLog(@"Match!");
            [tempArray addObject:charObj];
        }
    }
    [fullArray addObject:tempArray];
    [tempArray removeAllObjects];   //this empties it from fullArray too
}

}

我可以获取多少行和列的变量，但它们不是静态的。我曾尝试使用C数组，但无法以这种方式创建全局数组。我尝试定义一个全局数组并在create array中使用 new，但是Xcode表示 new无法识别。
我尝试过

I can get a variable for how many rows and columns, but they're not static. I've tried using C arrays, but I won't be able to make a global array that way. I tried defining a global array and using "new" in create array, but Xcode says "new" is unrecognized. I tried

id fullArray;//in global scope
fullArray=new id fullArray[rows][columns];//new and id throw exceptions, new unrecognized and id expects ";" before it.

我的另一种想法是创建一个单例，但是对于这个问题似乎有点过头了。当然，有一种方法可以处理需要数量未知的数组吗？

My other thought is to create a singleton, but it seems like overkill for this problem. Surely there's a way to handle needing an unknown number of arrays?

我将使用这些数组来填充具有多个部分的分组表格视图。

I'll be using the arrays to populate a grouped tableview with multiple sections. Maybe I'm going about this all wrong?

谢谢您的帮助。

推荐答案

更改大约2行就可以了。

Change just about 2 lines and you've got it.

- (void)createArray{

    fullArray=[[NSMutableArray alloc]init];

    for(int j=0; j<numberOfGames; j++){
        // inside loop
        NSMutableArray *tempArray=[[NSMutableArray alloc] init];

        for(int i=0; i<[appDelegate.hiddenChars count]; i++){
            Chars *charObj=[appDelegate.hiddenChars objectAtIndex:i];
            if(charObj.gameID==j){
                //NSLog(@"Match!");
                [tempArray addObject:charObj];
            }
        }
        [fullArray addObject:tempArray];
        [tempArray release]; // but fullArray still owns it
    }

}

这篇关于可变数组的二维NSMutableArray，但不知道我需要多少的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！