Implementation of LinkedList

JavaScript/MyLinkedList/list.js

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+//Constructor for list element - Node
+function Node(prev, next, value) {
+  this.prev = prev;
+  this.next = next;
+  this.value = value;
+}
+//Constructor for LinkedList
+function LinkedList() {
+   this.head = null;
+}
+//--------------------Add--------------------
+//Push elements to the start of the array
+LinkedList.prototype.unshift = (...args) => {
+  var current;
+  var prev = null;
+  var next = this.head;
+
+  for (let i = args.length - 1; i >= 0; i--) {
+      current = new Node(prev, next, args[i]);
+      next = current;
+  }
+
+  this.head = current;
+};
+//Push element to the end of array
+LinkedList.prototype.push = (val) => {
+  if (this.head == null){
+    this.head = new Node(null, null, val);
+  } else {
+    let current = this.head;
+    while (current.next != null){
+      current = current.next;
+    }
+    var item = new Node(current, null, val);
+    current.next = item;
+  }
+};
+//Insert elements inside of the list on the index
+LinkedList.prototype.insert = (index, value) => {
+  let current = this.head;
+  let i = 0;
+
+  while (current.next != null && index != i) {
+    current = current.next;
+    i++;
+  }
+
+  if (i == index){
+    if (i == 0){
+      this.head.prev = new Node(null, this.head, value);
+      this.head = this.head.prev;
+    } else {
+      var item = new Node(current.prev, current, value);
+      current.prev.next = item;
+    }
+  } else {
+    if (i == index - 1) {
+      current.next = new Node(current, null, value);
+    }
+  }
+};
+//Append elements to the end of list
+LinkedList.prototype.append = (...args) => {
+  let current = this.head;
+  while (current.next != null) {
+    current = current.next;
+  }
+  for (let i = 0; i < args.length; i++) {
+    LinkedList.prototype.add(args[i]);
+  }
+};
+//--------------------Find--------------------
+//Find first item with given value
+LinkedList.prototype.findFirst = (value) => {
+  let current = this.head;
+
+  do {
+    if (current.value == value)
+      return true;
+
+    current = current.next;
+  } while(current != null);
+
+  return false;
+};
+//Returns array of all items with given value
+LinkedList.prototype.findAll = (value) => {
+  let current = this.head;
+  let results = [];
+
+  do {
+    if (current.value == value)
+      results.push(current);
+
+    current = current.next;
+  } while(current != null);
+
+  return results;
+};
+//Find(if element is regular expression, we test if item is proper for it
+//and call callback function, if not we compare it as ordinal value
+//and call callback)
+LinkedList.prototype.find = (value, callback) => {
+  let current = this.head;
+
+  var comparator;
+
+  if (value instanceof RegExp) {
+    comparator = (current) => { return value.test(current.value); };
+  } else {
+    comparator = (current) => { return current.value == value; };
+  }
+
+  do {
+    if (comparator(current)) {
+      callback(current.value);
+    }
+    current = current.next;
+  } while(current != null);
+};
+//Add array of elements to the end of list
+LinkedList.prototype.append = (...args) => {
+  let current = this.head;
+  while (current.next != null) {
+    current = current.next;
+  }
+  for (let i = 0; i < args.length; i++) {
+    LinkedList.prototype.add(args[i]);
+  }
+};
+//--------------------Print--------------------
+LinkedList.prototype.print = () => {
+  let current = this.head;
+  while (current != null) {
+    console.log(current.value);
+    current = current.next;
+  }
+};
+//--------------------Remove--------------------
+//Removal from the start of list
+LinkedList.prototype.shift = () => {
+    if (this.head == null){
+      return null;
+    }
+    else{
+      var returnVal = this.head.value;
+
+      if (this.head.next == null) {
+         this.head = null;
+      }
+      else {
+        this.head = this.head.next;
+        this.head.prev = null;
+      }
+      return returnVal;
+    }
+}
+//Removal from the end of list
+LinkedList.prototype.pop = () => {
+  let current = this.head;
+  while (current.next != null) {
+    current = current.next;
+  }
+  current.prev.next = null;
+  return current.value;
+};
+//Removal of certain value in the list
+LinkedList.prototype.erase = (value) => {
+  let current = this.head;
+  while (current != null) {
+    if (current.value == value)
+      break;
+    current = current.next;
+  }
+
+  if (current != null){
+    if (current.next == null) {
+      current.prev.next = null;
+      current.prev = null;
+    } else if (current.prev == null) {
+      this.head = current.next;
+      this.head.prev = null;
+    }
+    else{
+       current.prev.next = current.next;
+       current.next.prev = current.prev;
+    }
+    LinkedList.prototype.erase(value);
+  }
+};
+
+//Module exports
+module.exports = LinkedList;

JavaScript/MyLinkedList/main.js

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+const LinkedList = require('./list.js');
+const lst = new LinkedList();
+//lst.push(9);
+for (let i = 0; i < 10; i++){
+  lst.push(i);
+}
+
+//lst.push(9);
+
+//lst.print();
+
+// //Find first test
+// console.log(lst.findFirst(0));
+// console.log(lst.findFirst(4));
+// console.log(lst.findFirst(9));
+// console.log(lst.findFirst(20));
+
+//Find all test
+// console.log(lst.findAll(1));
+
+//Find test
+// lst.find(1, (value) => {
+//   console.log(value);
+// });
+
+//Append test
+//lst.append(10,11,12,13,14);
+
+//lst.add("vova");
+// lst.print();
+
+//Find with RegExp test
+// lst.find(new RegExp("\w","g"), (value) => {
+//   console.log(value);
+// });
+//
+
+// var retUnshift = lst.shift();
+// console.log(retUnshift);
+// var retPop = lst.pop();
+// console.log(retPop);
+
+//lst.erase(0);
+//lst.erase(9);
+// lst.insert(0, "Vova");
+// lst.insert(4, "Vova1");
+// lst.insert(12, "Vova2");
+// lst.insert(12, "Vova3");
+
+var number = 0;
+lst.unshift("vova", "dima", "vitaliy", "oleksiy");
+lst.find(/^[a-z]*$/, (item) => {
+  console.log(number);
+  number++;
+});
+
+//lst.print();

JavaScript/MyLinkedList/package.json

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+{
+  "name": "lab1",
+  "version": "1.0.0",
+  "description": "the first laboratory work on NodeJS",
+  "main": "main.js",
+  "scripts": {
+    "test": "node main.js"
+  },
+  "author": "Volodymyr Novak",
+  "license": "ISC"
+}