Question

defined variable:

 LinkedList list1=new LinkedList();

Object get() in list1 obtains a node of list1

Object remove() in list1 deletes a node of list1

count() is length of list1

for(int i=1;i<list1.count();i++){
  if(list1.get(i).startsWith('"',0)) //Error here
    list1.remove(i);
}

Error: cannot find symbol

symbol: method charAt(int)
location: class Object

how to fix this problem?
I would like to delete the node in list1 which starts with (“).

Answer 1

1. startsWith is a method in the String class; you are using the raw LinkedList type, and thus it is treated like a LinkedList<Object>. If you wish to use Strings, make it a LinkedList<String>.
2. startsWith accepts only String arguments, not char arguments. Use startsWith("\"") instead.
3. The second parameter you’ve supplied to startsWith is superfluous; providing no second parameter will assume starting position as 0.
4. You have an extraneous semicolon after your if statement. This will cause the if body to be treated as empty. Definitely remove this semicolon and optionally use curly braces.

---

Your modified solution may look something like this:

LinkedList<String> list1 = new LinkedList<String>();

// [...] Populate the list accordingly here

for(int i=1; i < list1.count(); i++){
    if (list1.get(i).startsWith("\"")) {
        list1.remove(i);
    }
}

---

Additional notes:

1. Your for loop starts at index 1. Note that this will not remove over the first element. I’m sure if this is your desired behavior.
2. As you remove elements in the list, the indices of the latter elements in the list will change.

For example:

[ "a", "b", "c", "d" ]
   ^
(remove element at index 0)

[ "b", "c", "d" ]
        ^
(remove element at index 1... uh oh, we missed "b"!)

[ "b", "d" ]
              ^
(remove element at index 2... ERROR; index out of bounds)