How LinkedList is used as a stack and queue

Use as a stack

//定义栈
LinkedList<Integer> stack = new LinkedList<Integer>();

//push元素
stack.push(1)

//pop元素
stack.pop()

//获取栈顶元素，不弹出
stack.peek()

Use as a queue

//定义
LinkedList<Integer> queue = new LinkedList<Integer>();

//添加元素
queue.add(1);

//删除队列头元素
queue.poll();

//获取队列头元素，不删除
queue.peek();