在Java中展平二维或三维阵列

我需要取一个多维数组并将其展平，这样如果数组看起来像：

[1,2,3]
[4,5,6]

然后将其转换为：

[1,2,3,4,5,6]

我还需要适应3D阵列并将其展平

这是我到目前为止得到的

class ArrayOperations {
private int[] postFlattenedArray;

public ArrayOperations {

flattenedArray = new int[arrayDimensions[0]];
// arrayDimesnsions of 3,4 is a a 3x4 array; 3,4,5 is a 3x4x5 array

//set up ints to hold total size and dimensionality of array
int prod = 1
int dimensions = 0;

newArray = new int[prod - 1];

for (int i: arrayDimensions) {
  prod = prod * i;
  dimensions += 1;
  }
int k = 0;

for ( int i: arrayDimensions ){
for ( int j = 0; j <= i; j++ ){
  newArray[k++] = flattenedArray[j][0][0]
}
}

}

---

似乎最简单的解决方案是实现一个递归函数

flatte

（可能必须是泛型的，才能处理任何数组），如果已经是flat，它将返回数组本身，或者递归地调用所有内部数组并连接结果。

试试这个

static void flatten(Object object, List<Integer> list) {
    if (object.getClass().isArray()) 
        for (int i = 0; i < Array.getLength(object); ++i)
            flatten(Array.get(object, i), list);
    else
        list.add((int)object);
}

static int[] flatten(Object object) {
    List<Integer> list = new ArrayList<>();
    flatten(object, list);
    int size = list.size();
    int[] result = new int[size];
    for (int i = 0; i < size; ++i)
        result[i] = list.get(i);
    return result;
}

static void flatten(Object object, List<Integer> list) {
    if (object.getClass().isArray()) 
        for (int i = 0; i < Array.getLength(object); ++i)
            flatten(Array.get(object, i), list);
    else
        list.add((int)object);
}

static int[] flatten(Object object) {
    List<Integer> list = new ArrayList<>();
    flatten(object, list);
    int size = list.size();
    int[] result = new int[size];
    for (int i = 0; i < size; ++i)
        result[i] = list.get(i);
    return result;
}

int[][][] array = {
    {{1, 2, 3}, {4, 5}},
    {{6}, {7, 8, 9}},
};
System.out.println(Arrays.toString(flatten(array)));
// -> [1, 2, 3, 4, 5, 6, 7, 8, 9]