Question

There is an ArrayList “allVariables” that contain an array of integers. I need to find if this array contains the number 1. If it does, the answer should be false, otherwise true.

I wrote some code, but it results in java.lang.NullPointerException:

private boolean notIncluded(int ind, ArrayList<Color> c) {
    ArrayList<Integer[]> allVariables = new ArrayList<Integer[]>();
        // Filling the ArryList

    for (int k = 0; k < c.size(); k++) {
        allVariables.add(c.get(k).getColor()); // returns Integer[]
    }

    if (Arrays.asList(allVariables).contains(1)) {
        return false;
    }

    return true;
}

Answer 1

You need to check for nulls in your code. The following piece of code attempts implementation of what you need and checks for nulls in the process:

public function allVariablesContains(List<Integer[]> allVariables, int intToSearchFor)
{
    if (allVariables == null)
        return false;
    for (int i = 0; i < allVariables.Length; i++)
    {
        if (allVariables[i] == null)
            continue;
        if (Arrays.asList(allVariables).contains(intToSearchFor))
            return true;
    }
    return false;
}