Index 12 out of bounds for length 12. How can I fix this problem?

Question

Everytime I run the code I get an Index 12 out of bounds for length 12. I'm not sure what is the problem. Here is the code:

enter code here: int getDayNumber(int day,int month,int year) {
    if(this.leapYear(year)) {
        int months[] = {31,29,31,30,31,30,31,31,30,31,30,31};
        int cnt = 0 ;
        for(int i=0;i<month-1;i++) {
            cnt += months[i];
            System.out.println(cnt + "   " + i);
        }
        return cnt + day ; // count = cnt

You should validate that the ``month`` parameter is indeed less than 12 (it should be 0 - 11). — NomadMaker, Feb 28 '21 at 22:17
@ATP Yes, that's what he wrote. I'm sorry, but I don't understand why are you pointing this out to me? It should be ``i < month``, but he still has to verify that ``month`` is both >= 0 and < 12. — NomadMaker, Feb 28 '21 at 22:21
I did. I used month-1 just to see if it changes anything from i — Saitou9, Feb 28 '21 at 22:22
@Saitou9 Could you please show how you are calling the getDayNumber() method, including all the parameter values? — NomadMaker, Feb 28 '21 at 22:23
I figured it out. My professor put an error in the note when I run it. She put 21 in the text file and thats why I kept getting an out of bound error. — Saitou9, Feb 28 '21 at 22:31
and that's why you need input validation. or, at the very least, write your loop like `for(int i=0;i — user15187356, Mar 01 '21 at 01:03

score 0 · Answer 1 · answered Mar 02 '21 at 03:51

The (month - 1) that you've used inside the loop points to the month passed in the parameter in the function getDayNumber. Consider using .length function to calculate the length of the array. Try using for loop something like:

for(int i = 0 ; i < months.length ; i++)

Your concept of how Array works is pretty clear! Just use months.length and you're good to go. Tell me how this works out for you!

score 0 · Answer 2 · answered May 24 '21 at 05:11

    package projectlearn1;

public class ArrayQueue {
    private int[] mArray;
    private int mCount;

    public ArrayQueue(int sz) {
        mArray=new int[sz];
        mCount=0;
    }

    public void add(int val){
        mArray[mCount++]=val;
    }

    public int front(){
        return mArray[0];
    }

    public int pop(){
        int ret=mArray[0];
        mCount--;
        for (int i = 0; i < mCount; i++) {
            mArray[i-1]=mArray[i];
        }
        return ret;
    }
    public int size(){
        return mCount;
    }

    public boolean isEmpty(){
        return size()==0;
    }

    public static void main(String[] args) {
        int tmp=0;
        ArrayQueue astack=new ArrayQueue(12);
        astack.add(10);
        astack.add(20);
        astack.add(30);

        tmp=astack.pop();
        System.out.printf("tmp=%d\n",tmp);

        tmp=astack.front();
        System.out.printf("tmp=%d\n",tmp);

        astack.add(40);

        System.out.printf("isEmpty()=%b\n",astack.isEmpty());
        System.out.printf("size()=%d\n",astack.size());
        while (!astack.isEmpty()){
            System.out.printf("size()=%d\n",astack.pop());
        }
    }
}

我也遇到了相同的问题 Index -1 out of bounds for length 12 — GENIUS134679AA, May 24 '21 at 05:13
While this answer may be the correct solution, code-only answers aren't very helpful. Maybe you can add some text to the answer to make it more clear? — Skillzore, May 24 '21 at 09:25

score 0 · Answer 3 · edited Jan 28 '23 at 07:48

import java.util.*;
public class BinaryTreessssB {

    static class Node {
        int data;
        Node left;
        Node right;

        Node(int data) {
            this.data = data;
            this.left = null;
            this.right = null;
        }

    }
    static class BinaryTree{
        static int idx = -1;
        public static Node buildTree(int nodes[]){
            idx++;
            if (nodes[idx] == -1){
                return null;
            }
            Node newNode = new Node(nodes[idx]);
            newNode.left = buildTree(nodes);
            newNode.right = buildTree(nodes);


            return newNode;
        }

        public static void preorder(Node root){
            if (root == null){

            }
            System.out.println(root.data+" ");
            preorder(root.left);
            preorder(root.right);
        }

    }
    public static void main(String[] args) {
        int nodes[] = {1, 2, 4, -1, 5, -1, -1, 3, -1, 6, -1, -1};
        BinaryTree tree = new BinaryTree();
        Node root = tree.buildTree(nodes);
        tree.preorder(root);
    }
}

enter image description here

Your answer could be improved with additional supporting information. Please [edit] to add further details, such as citations or documentation, so that others can confirm that your answer is correct. You can find more information on how to write good answers [in the help center](/help/how-to-answer). — Community, Jan 19 '23 at 06:29

Index 12 out of bounds for length 12. How can I fix this problem?

3 Answers3