Implemented singly linked list queue in java

data_structures/04. Queues/java/SinglyLinkedListQueue.java

@@ -0,0 +1,63 @@
+class Node{
+    int val;
+    Node next;
+    Node(int val){
+        this.val = val;
+        this.next = null;
+    }
+}
+
+public class SinglyLinkedListQueue {
+    int length;
+    Node head;
+    Node tail;
+
+    public SinglyLinkedListQueue(){
+        this.head = null;
+        this.tail = null;
+        this.length = 0;
+    }
+
+    private void enqueue(int val){
+        Node newNode = new Node(val);
+
+        if(this.length == 0){
+            this.head = newNode;
+        }else{
+            this.tail.next = newNode;
+
+        }
+        this.tail = newNode;
+        this.length++;
+    }
+
+    private Integer dequeue(){
+
+        if(this.length == 0){
+            return null;
+        }
+
+        Node node = this.head;
+        if(this.length == 1){            
+            this.head = null;
+            this.tail = null;
+        }else{
+            this.head = this.head.next;
+        }
+
+        node.next = null;
+        length--;
+        return node.val;
+    }
+
+    public static void main(String[] args) {
+        SinglyLinkedListQueue sllq = new SinglyLinkedListQueue();
+        sllq.enqueue(0);
+        sllq.enqueue(2);
+        sllq.enqueue(3);
+        System.out.println(sllq.dequeue());
+        System.out.println(sllq.dequeue());
+        System.out.println(sllq.dequeue());
+        System.out.println(sllq.dequeue());
+    }
+}