Intermediate Java(14) - Stacks, push, pop

import java.util.*;

public class apples{

public static void main(String[] args){

Stack<String> stack = new Stack<String>();

stack.push("first"); → 放first入Stack

printStack(stack);

stack.push("second"); → 放second入Stack

printStack(stack);

stack.push("third"); → 放third入Stack

printStack(stack);

stack.pop(); → 收回Stack剛才(最後)放入的內容(third)

printStack(stack);

stack.pop(); → 收回Stack剛才(最後)放入的內容(second)

printStack(stack);

stack.pop(); → 收回Stack剛才(最後)放入的內容(first)

printStack(stack);

}

private static void printStack(Stack<String> s){

if(s.isEmpty())

System.out.println("you have nothing in Stack");

else

System.out.printf("%s TOP\n", s);

}

}

這是運行時的結果:

[first] TOP

[first, second] TOP

[first, second, third] TOP

[first, second] TOP

[first] TOP

you have nothing in Stack