Arraylist java.lang.IndexOutOfBoundsException: Index 3 out of bounds for length 3 Error

Question

I created a method which takes an Arraylist of string and an integer. It's going to remove all string whose length is less than the given integer.

For example:

Arraylist = ["abcde", "aabb", "aaabbb", "abc", "ab"]

integer = 4

So the new Arraylist should be: ["abcde", "aabb", "aaabbb"]

But I'm getting this error message:

Exception in thread "main" java.lang.IndexOutOfBoundsException: Index 3 out of bounds for length 3

Here is my code:

public static void main(String[] args){
        ArrayList<String> newArrayList = new ArrayList<>();
        newArrayList.add("string1");
        newArrayList.add("string2");
        newArrayList.add("rem");
        newArrayList.add("dontremove");
        removeElement(newArrayList, 4); // new arraylist must be = [string1, string2, dontremove]
    }


    public static void removeElement(ArrayList<String> arraylist, int inputLen){
        int arrayLen = arraylist.size();
        for(int i=0; i<arrayLen; i++){
            if(arraylist.get(i).length() < inputLen){
                arraylist.remove(i);
                i--;
            }
        }
        System.out.println("New Arraylist: " + arraylist);
    }

What's wrong with this code?

Answer 1

You're looping from 0 to the size of the array which is 4. Inside the loop you're removing items so the size of the array becomes less than 4, so you get this exception. Try looping like this:

Iterator<String> iterator = arraylist.iterator();

while (iterator.hasNext()) {
    String word = iterator.next();
    if (word.length() < inputLen) {
        iterator.remove();
    }
}