How exactly node == null checks if the stack is full?

If the new node we created is null (nothing), how is it not referring to the stack as empty but instead checks if the stack is full?

 //push() function    public void push(int x) {            //create a new node and allocate memory      Node node = new Node();        //check if the stack is full i.e check for stack overflow      if(node == null) {          System.out.println("\n Stack is full. Stack Overflow!");          return;      }      node.data = x;      node.next = head;      head = node;  }    //check for an empty stack  public boolean isEmpty() {       return head == null;  }  

https://stackoverflow.com/questions/66937400/how-exactly-node-null-checks-if-the-stack-is-full April 04, 2021 at 09:59AM