package my.collection.linearTest; import my.collection.linear.MyStack; public class MyStackTest { public static void main(String[] args) { MyStack ms = new MyStack(); System.out.println(ms.isEmpty()); ms.push("a"); System.out.println(ms.isEmpty()); ms.push("b"); //a,b System.out.println(ms.size()); ms.pop(); ms.pop(); //null System.out.println(ms.isEmpty()); ms.push("zzz"); //zzz System.out.println(ms.peek()); ms.push("yyy"); //zzz,yyy System.out.println(ms.peek()); } }