# JavaScript Exercises: Check whether a Doubly Linked Lists is empty or not

## JavaScript Data Structures: Exercise-3 with Solution

Write a JavaScript program to check whether a Doubly Linked Lists is empty or not. Return true otherwise false.

Sample Solution:

JavaScript Code:

``````class Node {
constructor(value) {
this.value = value;
this.next = null;
this.previous = null;
}
}

constructor(value) {
value: value,
next: null,
previous: null
};
this.length = 0;
}

// Insert node at end of the list

this.tail = newNode;
}
else
{
newNode.previous = this.tail;
this.tail.next = newNode;
this.tail = newNode;
}

this.length++;
}

size() {
return this.length;
}

is_Empty(){
return this.length === 0;
};

printList() {
let result = [];
while (current !== null) {
result.push(current.value);
current = current.next;
}
console.log(result.join(' '));
return this;
}
}

numList.printList();
new_numList.printList();
```
```

Sample Output:

```Original Doubly Linked Lists:
2 3 5 6 8
Check the said Doubly Linked lists is empty or not! false

Check the said Doubly Linked lists is empty or not! true
```

Flowchart:

Live Demo:

See the Pen javascript-doubly-linked-list-exercise-3 by w3resource (@w3resource) on CodePen.

Improve this sample solution and post your code through Disqus

Linked List Previous: Count number of nodes in a Doubly Linked Lists.

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## JavaScript: Tips of the Day

Shorten an array using its length property

A great way of shortening an array is by redefining its length property.

```let array = [0, 1, 2, 3, 4, 5, 6, 6, 8, 9]
array.length = 4
// Result: [0, 1, 2, 3]
```

Important to know though is that this is a destructive way of changing the array. This means you lose all the other values that used to be in the array.

Ref: https://bit.ly/2LBj213