Remove elements from singly linked list in JavaScript

JavascriptWeb DevelopmentFront End TechnologyObject Oriented Programming

Suppose, we have a singly linked list like this −

const list = {
   value: 1,
   next: {
      value: 2,
      next: {
         value: 3,
         next: {
            value: 4,
            next: {
               value: 5,
               next: {
                  value: 6,
                     next: {
                        value: 7,
                        next: null
                     }
                  }
               }
            }
         }
      }
};

We are required to write a JavaScript function that takes in one such list as the first argument and a number as the second argument.

The function should search whether there exists a node with that value in the list, if it does, the function should remove the node from the list.

Example

The code for this will be −

const list = {
   value: 1,
   next: {
      value: 2,
      next: {
         value: 3,
         next: {
            value: 4,
            next: {
               value: 5,
               next: {
                  value: 6,
                  next: {
                     value: 7,
                     next: null
                  }
               }
            }
         }
      }
   }
};
const recursiveTransform = (list = {}) => {
   if(list && list['next']){
      list['value'] = list['next']['value'];
      list['next'] = list['next']['next'];
      return recursiveTransform(list['next']);
   }else{
      return true;
   };
}
const removeNode = (list = {}, val, curr = list) => {
   // end reached and item not found
   if(!list){
      return false;
   }
   if(list['value'] !== val){
      return removeNode(list['next'], val, list);
   };
   return recursiveTransform(list);
};
console.log(removeNode(list, 3));
console.log(JSON.stringify(list, undefined, 4));

Output

And the output in the console will be −

true
{
   "value": 1,
   "next": {
      "value": 2,
      "next": {
         "value": 4,
         "next": {
            "value": 6,
            "next": {
               "value": 7,
               "next": null
            }
         }
      }
   }
}
raja
Published on 25-Nov-2020 16:26:39
Advertisements