Comp Sci Java NoSuchElementException error

[magnifik]

I am writing code for a doubly linked list, but when I try to compile it, I am getting an error when trying to throw the NoSuchElementException() function. Here is the part of the code concerning the issue:

// _size is an integer that keeps track of the number of elements. in this case, i am checking if the list is empty
public Object removeBack() {
if (_size == 0) {
throw new NoSuchElementException();
}
Node node = new Node();
Node cursor = _tail._prev;
cursor._next._prev = cursor._prev;
cursor._prev._next = cursor._next;
_size--;
}

i am wondering.. what's wrong with it? am i calling it incorrectly?

 

[Mark44]

I am writing code for a doubly linked list, but when I try to compile it, I am getting an error when trying to throw the NoSuchElementException() function. Here is the part of the code concerning the issue:

// _size is an integer that keeps track of the number of elements. in this case, i am checking if the list is empty
public Object removeBack() {
if (_size == 0) {
throw new NoSuchElementException();
}
Node node = new Node();
Node cursor = _tail._prev;
cursor._next._prev = cursor._prev;
cursor._prev._next = cursor._next;
_size--;
}

i am wondering.. what's wrong with it? am i calling it incorrectly?

NoSuchElementException is used when an enumeration doesn't have a particular element. I think you want to use NoSuchFieldException.

 

[magnifik]

i tried to change it to NoSuchFieldException, but I am still getting the same error.

 

[Mark44]

What's the error that you're getting?

 

[magnifik]

What's the error that you're getting?

Cannot find symbol

 

[I like Serena]

Hi magnifik!

Try adding:

import java.util.NoSuchElementException;

before using it.

 

[magnifik]

i got it to work by removing the {} symbols.

 

[Mark44]

i got it to work by removing the {} symbols.

They're called braces. In any case, that doesn't make sense to me. Your removeBack method looked fine to me with them, so removing the braces on your if statement shouldn't have made any difference.

 

[magnifik]

They're called braces. In any case, that doesn't make sense to me. Your removeBack method looked fine to me with them, so removing the braces on your if statement shouldn't have made any difference.

It doesn't make sense to me either, but I didn't change any of my code except for the removal of the brackets and it wasn't throwing an error.

 

[I like Serena]

It doesn't make sense to me either, but I didn't change any of my code except for the removal of the brackets and it wasn't throwing an error.

So add the curly braces again and check if it throws an error again.
To be honest, I expect that it won't throw an error.