CODEWITHSUNDEEP
javaarraysalgorithmdata-structures
Jose
Jose

Reputation: 340

"Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: 100" in array data structure program

I am writing a program that creates an array with 100 random (long) elements:

main

byte maxSize = 100;
HighArray arr = new HighArray(maxSize);

for (byte j =0; j < maxSize; j++)
arr.insert((long)(Math.random()*99));

When I call the removeMax() method which is in the HighArray class

public long getMax()
    {
        long max = -1;

        for (byte i =0; i < nElems; i++)
        {
            if(max < a[i])
                max = a[i];
        }

        return max;
    }

    public long removeMax()
    {
        long max = getMax();
        delete(max);
        return max;
    }

public boolean delete(long value)
    {
        int j;
        for(j=0; j<nElems; j++)        // look for it
            if( value == a[j] )
                break;
        if(j==nElems)                  // can't find it
            return false;
        else                           // found it
        {
            for(int k=j; k<nElems; k++) // move higher ones down
                a[k] = a[k+1];
            nElems--;                   // decrement size
            return true;
        }

I get the array out of bounds : 100 exception. I assume this means that my array is out of bounds by 100 elements, which doesn't make sense to me since I'm deleting elements from it, not adding any. I did not get any errors when I initially created the array.

According to my IDE (Intellij IDEA), the problem happens when I call removeMax() from main.

If I am misunderstanding the error please let me know and clarify it for me. If more details or code is needed, let me know.

Upvotes: 2

Views: 315

Answers (1)

BlackHatSamurai
BlackHatSamurai

Reputation: 23503

From what I can tell with the code you have, the problem is here:

a[k] = a[k+1];

Do this instead:

a[k] = a[k-1];

You assign K the value of J, and when J is on the last iteration (100), you add 1 to it, and thus get a value of 101, which is more than the allotted 100.

Upvotes: 1

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