CODEWITHSUNDEEP
javaarraysmultidimensional-array
user181421
user181421

Reputation: 57

Copying array elements within multidimensional arrays in Java

So I'm having some trouble with this in java. This method is supposed to take in two String arrays which are multidimensional. This method is supposed to return a a copy String array. Now these two arrays that are being sent to the copy method are going to have randomly generated lengths within the arrays. I am trying to see if array2 is smaller than array and if it is then array will be assigned the length of array2 and I want to copy elements from array into array2. If it is the opposite with array2 being bigger than array then I would like to copy the elements from array into array2 and then the REMAINING spots in array2 will get filled with an *. Now the issue is I keep getting runtime errors with out of bounds for the index. It is specifically the lines that I have indicated with double asterisks below(within for loops) that are giving me issues. What could I do to solve the issue. 

    public static String[][][] copy(String[][][] array, String[][][] array2){
    if(array2.length < array.length){
        array = new String[array2.length][array2.length][array2.length];
        for(int i = 0; i < array2.length; i++){
            for(int j = 0; j < array2[i].length; j++){
                for(int k = 0; k < array2[i][j].length; k++){
                    **array2[i][j][k] = array[i][j][k];**
                }
            }
        }
        return array2; 
    }
    if(array2.length > array.length){

        for(int i = 0; i < array.length; i++){
            for(int j = 0; j < array[i].length; j++){
                for(int k = 0; k < array[i][j].length; k++){
                    **array2[i][j][k] = array[i][j][k];**
                }
            }
        }
        for(int i = array.length - 1; i < array2.length; i++){
            for(int j = array[i].length - 1; j < array2.length; j++){
                for(int k = array[i][j].length - 1; k < array2.length; k++){
                    array2[i][j][k] = "*";
                }
            }
        }
        return array2;
    }
    return array;
}

Upvotes: 0

Views: 48

Answers (1)

Vampire
Vampire

Reputation: 38639

You assume that each dimension of the array is of equal size.
But you cannot even assume that two sibling arrays are of equal size.
What I mean is, that array = new String[array2.length][array2.length][array2.length]; is nonsense and at least in two ways.
You probably want to have array2 = new String[array.length][][], because if you reassign array you will just copy nulls around. And for the lengths of the other dimensions you have to do the same comparisons and resizings, especially if you did not reassign the array2. If you did, then you have to create the sub-level arrays afresh anyway.

Upvotes: 1

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