public class StackOfInts {
private int[] stack;
//index of last item in the stack + 1//来自 时 代 J a v a 公 众 号 - N o w J a v a . c o m
private int next = 0;
public StackOfInts(int size) {
//create an array large enough to hold the stack
stack = new int[size];
}
public void push(int on) {
//push an integer onto the stack
if (next < stack.length) {
stack[next++] = on;
}
}
//来 自 N o w J a v a . c o m
public boolean isEmpty() {
//check if the stack is empty
return (next == 0);
}
public int pop() {
//pop an integer from the stack
if (!isEmpty()) {
// next item in the stack
return stack[--next];
} else {
return 0;
}
}
public int getStackSize() {
//get the size of the stack
return next;
}
//class that steps through the stack
//not related to the stack functionality.
private class StepThrough {
// start stepping through the stack at i=0 with step 2
private int i = 0;
// retrieve the current element
public int getNext() {
//get a next value in the stack
int retValue = stack[i];
if (i < stack.length) {
i = i + 2;
}
return retValue;
}
//last element in the stack?
public boolean hasNext() {
return (i < getStackSize());
}
}
//utility method for creating a new StepThrough class instance
public StepThrough stepThrough() {
return new StepThrough();
}
public static void main(String[] args) {
//instantiate the outer class as "stackOne"
StackOfInts stackOne = new StackOfInts(15);
//populate the stackOne
System.out.print("Pushing elements into the stack: ");
for (int j = 0; j < 15; j++) {
System.out.print("" + j + " ");
stackOne.push(j);
}
System.out.println();
System.out
.println("Iterating through the whole stack selecting only even indexes:");
//instantiate the inner class as "iterator"
StepThrough iterator = stackOne.stepThrough();
//print out the stackOne[i]
while (iterator.hasNext()) {
System.out.print(iterator.getNext() + " ");
}
System.out.println();
System.out.println("Popping all elements from the stack:");
for (int j = 0; j < 15; j++) {
System.out.print(stackOne.pop() + " ");
}
}
}
/*
* Copyright (c) 1995, 2008, Oracle and/or its affiliates. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* - Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* - Neither the name of Oracle or the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
* IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
/**代码未完, 请加载全部代码(NowJava.com).**/
本文系作者在时代Java发表,未经许可,不得转载。如有侵权,请联系nowjava@qq.com删除。