CODEWITHSUNDEEP
javalist
jdk
jdk

Reputation: 39

Check if an element is removed java

I'd like to check if an element is removed from a list using java.

The first method is to remove the element, and then I create a new method to check if it is deleted:

public void removeElement(int index){
    try { 
        element.remove(index);
    } catch(IndexOutOfBoundsException e){
        System.out.println("Please enter an index number between 0 and "+e);
    }
}

public void removeElement (Element element) {
    boolean removed;
    if(element==null) {
        removed=true;
    }
    else {
        removed=false;
    }

No error appears, just a warning saying "The value of the local variable removed is not used."

Upvotes: 2

Views: 1630

Answers (2)

Nicholas K
Nicholas K

Reputation: 15433

Given the list :

List<Element> myList = new ArrayList<>();

You could change your removeElement() method to the following: 

public boolean removeElement (Element element) {
   return myList.remove(element);
}

Here if the element was successfully removed, it would return true else it would remove false. (Also since this a custom class you need to override the equals() and hashcode() methods.

You are receiving this warning

"The value of the local variable removed is not used."

because in removeElement (Element element) you are not returning the value of the variable removed so its value is not being used anywhere.

Upvotes: 1

Aditya Narayan Dixit
Aditya Narayan Dixit

Reputation: 2119

You can use list.contains() to check if the Element exists in the List. But for that to work, your class Element needs to have equals and hashcode() methods over-ridden because contains internally uses them to check for the equality.

Upvotes: 0

Related Questions