Scaling a 2D array by a factor of two

Question

This program is supposed to scale an array holding objects in each cell by a factor of two. For example, the array:

[[Object1,Object2],
 [Object3,Object4]]

should become:

[[Object1,Object1,Object2,Object2],
 [Object1,Object1,Object2,Object2],
 [Object3,Object3,Object4,Object4],
 [Object3,Object3,Object4,Object4]]

This is the code I have for the program so far:

public Color[][] doOperation(Color[][] imageArray)
{
    int multiplier = 2;  
    Color[][] newArray = new Color[imageArray.length*2][imageArray[0].length*2];

    for(int i = 0; i < imageArray.length; i++)
        for(int j = 0; j < imageArray[0].length; j++)
        {
            newArray[i][j] = imageArray[i/multiplier][j/multiplier];
        }
}

How should I change this code so that the new array is scaled properly? Any help is appreciated.

Answer 1

You mixed up your newArray and imageArray. You initialize double-sized newArray (this is right) but then iterate over it, using imageArray length. Just swap imageArray.length to newArray.length. And don't forget about return ;)

public static Color[][] doOperation(Color[][] imageArray) {
    int multiplier = 2;
    Color[][] newArray = new Color[imageArray.length*2][imageArray[0].length*2];

    for(int i = 0; i < newArray.length; i++)
        for(int j = 0; j < newArray[0].length; j++) {
            newArray[i][j] = imageArray[i/multiplier][j/multiplier];
        }
    return newArray;
}