What does ArrayIndexOutOfBoundsException mean and how do I get rid of it? Here is a code sample that triggers the exception:

Question

I have been working on some code in java and I just ran into an error and i'm not sure why because I just ran some code that was just like this and it worked just fine.

    String [] month = {"Jan", "Feb", "Mar", "Apr", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec" };

    double [] temperature ={54.3, 57.0, 62.5, 67.6, 74.3, 79.2, 80.9, 80.4, 77.8, 70.1, 62.8, 56.3};    
    double [] precipitation ={3.5, 3.4, 4.3, 2.9, 3.2, 6.8, 6.1, 6.6, 4.4, 2.5, 2.2, 2.6};  
 for( int index = 0; index < temperature.length; index++)
    {
        System.out.print(""+month [index] +".        "+temperature [index]+"         "+precipitation [index]);
        System.out.println();
    }

Possible duplicate of [What causes a java.lang.ArrayIndexOutOfBoundsException and how do I prevent it?](https://stackoverflow.com/questions/5554734/what-causes-a-java-lang-arrayindexoutofboundsexception-and-how-do-i-prevent-it) — GBlodgett, Jun 25 '18 at 01:59
It is not, that post inspired me to ask this question because I had the same problem, just for different reasons. — user9986762, Jun 25 '18 at 02:04

score 1 · Accepted Answer · answered Jun 25 '18 at 01:42

From inspection, I can see that your month array is missing the month of May, and therefore only has 11 elements in it. As a result, when you iterate over the 12 elements in the temperature array, you will get an array out of bounds exception during the final temperature, because there is no corresponding enter in month at that position.

To fix this, just make sure that month and temperature are the same size:

String [] month = {"Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep",
    "Oct", "Nov", "Dec" };

Ah thanks didn't catch that. – user9986762 Jun 25 '18 at 01:44 — user9986762, Jun 25 '18 at 01:44

What does ArrayIndexOutOfBoundsException mean and how do I get rid of it? Here is a code sample that triggers the exception:

1 Answers1