How do I check if an array is in another array?

Question

Here, I have an array in Java, lose, that has two arrays inside of it: xLose and yLose.

    int[] xLose = selectLose(buttons, xNum);
    int[] yLose = selectLose(buttons, yNum);
    int[][] lose = {xLose, yLose};

I already have a method that can check if an element is an array:

public boolean isInArray(int num, int[] array)
{
    for (int i = 0; i < array.length; i++)
    {
        if(num == array[i])
        {
            return true;
        }
    }
    return false;
}

But how do I check if an array is an element of an array of arrays? For example, is xLose in lose?

You do the same thing, if you are testing identity. Just make num be int[] and make array be int[][]. — dsh
– dsh, Commented Aug 11, 2015 at 18:09
num will never equal array[i] .... regardless of the language, you need to break up array[i] so that it looks at the first place holder (which is xlose) in array[i]... Right now this formulates to num == array[i] == {xLose,yLose} ... which will never be true. — Nefariis
– Nefariis, Commented Aug 11, 2015 at 18:10
The isInArray is checking if a number is in a one-dimensional array. Why can't num == array[i]? array[i] is an int and num is an int also. — michaeljan
– michaeljan, Commented Aug 11, 2015 at 18:16

Tony Tuttle · Accepted Answer · 2015-08-11 18:32:44Z

1

import java.util.Arrays;

public boolean isInArray(int[] sub, int[][] sup){
    for(int i=0; i<sup.length; i++)
        if(Arrays.equals(sub, sup[i]))
            return true;
    return false;
}

answered Aug 11, 2015 at 18:32

Tony Tuttle

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Comments

Shell Scott · Accepted Answer · 2015-08-11 18:35:34Z

0

Better use collection, there things are more simpler)

answered Aug 11, 2015 at 18:35

Shell Scott

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Comments

Ing Edwin Frias · Accepted Answer · 2015-08-11 18:52:29Z

0

you need to do something like this:

public boolean ArrayisInArray(int[] array1, int[][] array2)
{
    int cont=0;
    for (int i = 0; i < array2.length; i++)
    {          
      for (int j = 0; j < array2.length; i++)
      {
          if (array1[j]==array2[i][j])  
           cont++;

         if (cont == array1.length)
             return true;
      }
      cont=0;
    }
    return false;
}

this code can compare array1 with array2 row by row finding your first array in the second array

answered Aug 11, 2015 at 18:52

Ing Edwin Frias

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