ArrayIndexOutOfBoundsException confusion

From:

"phillip.s.powell@gmail.com" <phillip.s.powell@gmail.com>

Newsgroups:

comp.lang.java.help

Date:

11 Jan 2007 14:19:39 -0800

Message-ID:

<1168553979.308142.169310@i39g2000hsf.googlegroups.com>

    private final String[] buttonNameArray = {"cButton", "ceButton",
    "percentButton", "sqrtButton", "plusButton", "mcButton", "button7",
"button8",
    "button9", "dashButton", "mrButton", "button4", "button5",
"button6",
    "starButton", "mDashButton", "button1", "button2", "button3",
"slashButton",
    "mPlusButton", "plusDashButton", "dotButton", "button0",
"equalButton"};

    private final String[] buttonValArray = {"CE", "%", "\u221a", "+",
    "MC", "7", "8", "9", "-", "MR", "4", "5", "6", "*", "M-", "1", "2",
"3", "/",
    "M+", "+/-", ".", "0", "="};

private Hashtable buttonHash = null;

private void initComponents() {

  this.buttonHash = new Hashtable();
  for (int i = 0; i < this.buttonNameArray.length; i++) {
    this.buttonHash.put(this.buttonNameArray[i],
this.buttonValArray[i]);
  }

}

Output:

Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: 24
        at JCalculator.initComponents(JCalculator.java:44)
        at JCalculator.<init>(JCalculator.java:32)
        at JCalculator.main(JCalculator.java:66)
Java Result: 1

How on earth is this spawning an ArrayIndexOutOfBoundsException? I
don't see how that is possible as the array pointer should be at 0 and
there are a lot more than 0 elements in the final array.

Help appreciated, I am totally not understanding.

Phil