IndexOutOfBoundsException With Android ArrayList

I've got a very annoying problem with some code throwing an IndexOutOfBoundsException and I really cannot understand why. The logcat points to the 'addTimetableItem' of the followi

Solution 1:

You should accept @Tim's or @Graham's answer, this is just an addendum. They're correct about your size()+1 going past the end of the array.

If you're having difficulty using indexes to properly get everything out of the list, you can also try using a for-each loop (depending on the version of the Android SDK you're using). I'm assuming sortedFridayTimes is a list of class TimetableItem since you don't specify.

So this:

if(sortedFridayTimes.size()>0){
    insertDay("Friday");
    for(int i=1; i<sortedFridayTimes.size()+1;i++){
        addTimetableItem(sortedFridayTimes.get(i));
    }
}

Becomes this:

if(!sortedFridayTimes.isEmtpy()){
    insertDay("Friday");
    for(TimetimeItem item : sortedFridayTimes){
        addTimetableItem(item);
    }
}

A little cleaner if you don't actually need to use i anywhere.

Solution 2:

i<sortedFridayTimes.size()+1

You are looping past the last element in the array. Why the +1?

If there are N elements in the array, then the elements are from indexes 0 through to N-1.

So it should be:

for(int i=0; i<sortedFridayTimes.size(); i++) {

Solution 3:

The last loop in your for loop runs:

sortedFridayTimes.get(sortedFridayTimes.size())

This will always be out of bounds, because the elements are zero indexed.

For example, if the array size is "5", then you cannot access index "5", because the 5 elements in the array are 0,1,2,3,4.