[FIXED] ArrayListexception

Issue

I'm trying to write a util to handle the max/min of the arraylist elements.

In my code, I first set the if conditionyour textif (list.size()!= 0) ; to ensure that the list has elements:

public static int getMin(ArrayList<Integer> list)
    {
        int tmp = -1;
        if (list.size()!= 0) ;
        {
            tmp = list.get(0);
            for (int i = 0; i < list.size(); i++)
            {
                if (list.get(i) < tmp)
                {
                    tmp = list.get(i);
                }
            }
            return tmp;
        }
    }

but the IDE always indicate that the line:tmp = list.get(0);is causing indexOutofBounds exception. Why does the if condition I set not working? Maybe it is the static that makes this function not working as I wish. How can I correctly do it?

My whole code is shown below:

package util;

import java.util.ArrayList;

public class ListUtils
{
    public static void sort(ArrayList<Integer> list)
    {
        for (int i = 0; i < list.size() - 1; i++)
        {
            for (int j = 0; j < list.size() - 1 - i; j++)
            {
                if (list.get(j) > list.get(j + 1))
                {
                    int tmp = list.get(j);
                    list.set(j, list.get(j + 1));
                    list.set(j + 1, tmp);
                }
            }
        }
    }

    public static int getMax(ArrayList<Integer> list)
    {
        int tmp = -1;
        if (list.size() !=0) ;
        {
            tmp = list.get(0);
            for (int i = 0; i < list.size(); i++)
            {
                if (list.get(i) > tmp)
                {
                    tmp = list.get(i);
                }
            }
        }
        return tmp;
    }

    public static int getMin(ArrayList<Integer> list)
    {
        int tmp = -1;
        if (list.size()!= 0) ;
        {
            tmp = list.get(0);
            for (int i = 0; i < list.size(); i++)
            {
                if (list.get(i) < tmp)
                {
                    tmp = list.get(i);
                }
            }
            return tmp;
        }
    }

    //求平均值
    public static float getAvg(ArrayList<Integer> list)
    {
        int sum = -1;
        float avg = -1;
        if (list.size() != 0) ;
        {
            for (int i = 0; i < list.size(); i++)
            {
                sum += list.get(i);
            }
            avg = (float) sum / list.size();
            return avg;
        }
    }


}
```java

Fix the code to make it robust to handle the 0 element condition.

Solution

You have a ; after your if statement which ends the block right there and making whats inside the block to always execute

Answered By - Yonatan Nir
Answer Checked By - Timothy Miller (JavaFixing Admin)