js出栈入栈

栈（Stack）是一种线性数据结构，它具有后进先出（Last In First Out，LIFO）的特性。栈可以用数组或链表来实现，这里我以数组为例来演示。

JavaScript中没有专门的栈数据类型，但可以使用数组来模拟栈。对于数组模拟栈，入栈操作使用push()方法，出栈操作使用pop()方法。具体实现如下：

// 初始化一个空栈
let stack = [];

// 入栈
stack.push(1);
stack.push(2);
stack.push(3);

// 出栈
let item = stack.pop();
console.log(item); // 输出3

// 查看栈顶元素
let topItem = stack[stack.length - 1];
console.log(topItem); // 输出2

通过上面的代码，你可以看到如何使用JavaScript数组来模拟栈的入栈和出栈操作。需要注意的是，使用数组模拟栈时，要确保栈的大小不超过数组的长度，否则会导致栈溢出。

相关问题

实现顺序栈的基本操作。 1.initStack(S):栈S的初始化； 2.isEmpty(S):判断S是否栈空； (测试时，将栈清空，然后再删除，看是否有异常处理机制) 3.isFulI(S):判断S是否栈满； (测试时，将栈清空，然后再入栈，看是否有异常处理机制) 4. getTop(S):取栈顶元素，并返回该元素； 5. Push(S,x):将值为x的元素入栈； 6. Pop(S):出栈，并返回出栈的元素； 7. printStack(S):打印所有栈元素。

8. 创建StudentController.java控制器

在src/main/java/com/jr/controller目录下创建StudentController.java控制器，并添加以下内容：

package com.jr.controller;

import java.io.IOException;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.context.support.SpringBeanAutowiringSupport;

import com.fasterxml.jackson.databind.ObjectMapper;
import com.jr.domain.Student;
import com.jr.domain.StudentService;

@WebServlet("/student/*")
public class StudentController extends HttpServlet {
    
    private static final long serialVersionUID = 1L;
    
    @Autowired
    private StudentService studentService;
    
    @Override
    public void init() throws ServletException {
        super.init();
        SpringBeanAutowiringSupport.processInjectionBasedOnServletContext(this, getServletContext());
    }
    
    @Override 
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        String path = request.getPathInfo();
        if (path == null || path.equals("/list")) {
            String sNum = request.getParameter("sNum");
            String name = request.getParameter("name");
            String gender = request.getParameter("gender");
            int currentPage = Integer.parseInt(request.getParameter("currentPage"));
            List<Student> studentList = studentService.getStudentList(sNum, name, gender, currentPage);
            int totalCount = studentService.getTotalCount(sNum, name, gender);
            int totalPage = (totalCount % 10 == 0) ? (totalCount / 10) : (totalCount / 10 + 1);
            Map<String, Object> resultMap = new HashMap<String, Object>();
            resultMap.put("studentList", studentList);
            resultMap.put("totalCount", totalCount);
            resultMap.put("totalPage", totalPage);
            ObjectMapper objectMapper = new ObjectMapper();
            String json = objectMapper.writeValueAsString(resultMap);
            response.setContentType("application/json;charset=utf-8");
            response.getWriter().write(json);
        } else if (path.equals("/add")) {
            String sNum = request.getParameter("sNum");
            String name = request.getParameter("name");
            String gender = request.getParameter("gender");
            int age = Integer.parseInt(request.getParameter("age"));
            String tel = request.getParameter("tel");
            Student student = new Student();
            student.setsNum(sNum);
            student.setName(name);
            student.setGender(gender);
            student.setAge(age);
            student.setTel(tel);
            studentService.addStudent(student);
            response.sendRedirect(request.getContextPath() + "/index.jsp");
        } else if (path.equals("/update")) {
            int studentID = Integer.parseInt(request.getParameter("studentID"));
            String sNum = request.getParameter("sNum");
            String name = request.getParameter("name");
            String gender = request.getParameter("gender");
            int age = Integer.parseInt(request.getParameter("age"));
            String tel = request.getParameter("tel");
            Student student = new Student();
            student.setStudentID(studentID);
            student.setsNum(sNum);
            student.setName(name);
            student.setGender(gender);
            student.setAge(age);
            student.setTel(tel);
            studentService.updateStudent(student);
            response.sendRedirect(request.getContextPath() + "/index.jsp");
        } else if (path.equals("/delete")) {
            int studentID = Integer.parseInt(request.getParameter("studentID"));
            studentService.deleteStudent(studentID);
            response.sendRedirect(request.getContextPath()好的，以下是实现顺序栈的基本操作的代码：

class Stack:
def __init__(self + "/index.jsp");
}
}

}

9. 创建index.jsp页面

在src/main/webapp目录下创建, size):
        self.size = size
        self.stack = [None] * size
        self.top = -1

    def isEmptyindex.jsp页面，并添加以下内容：

<%@page contentType="text/html;charset=UTF-8" language="java"%>
(self):
return self.top == -1

def isFull(self):
return self.top == self.size - 1

def<%@taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>
<!DOCTYPE html>
<html>
getTop(self):
if self.isEmpty():
raise Exception("Stack is empty.")
return self.stack[self.top]

def push(self, x):
if self.isFull():
raise Exception("Stack is full.")
self.top += 1
self.stack[self.top]<head>
<meta charset="UTF-8">
<title>JavaWebProject</title>
<script src="https://cdn.bootcdn.net/ajax/libs/jquery = x

def pop(self):
if self.isEmpty():
raise Exception("Stack is empty.")
x = self.stack[self.top]
/3.6.0/jquery.min.js"></script>
<style>
table, th, td {
border: 1px solid black self.top -= 1
return x

def printStack(self):
if self.isEmpty():
print("Stack is empty.")
;
border-collapse: collapse;
text-align: center;
padding: 5px;
}
.pagination {
display else:
print("Stack elements are:")
for i in range(self.top, -1, -1):
print(self.stack[i: inline-block;
}
.pagination a {
color: black;
float: left;
padding: 8px 16])

在上述代码中，我们定义了一个`Stack`类，包含了栈的基本操作函数。`px;
        text-decoration: none;
        border: 1px solid #ddd;
    }
    .pagination a.active {
        background__init__`函数初始化栈，`isEmpty`函数判断栈是否为空，`isFull`函数判断栈是否已满，`-color: #4CAF50;
        color: white;
        border: 1px solid #4CAF50;
    }
    .paginationgetTop`函数获取栈顶元素，`push`函数将元素入栈，`pop`函数将元素出栈 a:hover:not(.active) {background-color: #ddd;}
    .add-form, .update-form {
        display: none;
        position并返回，`printStack`函数打印栈中的所有元素。

javaScript 字符串是否为回文

以下是三种JavaScript判断字符串是否为回文的方法：

1. 将字符串翻转，判断翻转后的字符串和原字符串是否相等

function isPalindrome(str) {
  var reversedStr = str.split('').reverse().join('');
  return str === reversedStr;
}

2. 使用双指针法，从字符串的两端开始向中间扫描，判断对应字符是否相等

function isPalindrome(str) {
  var left = 0, right = str.length - 1;
  while (left < right) {
    if (str[left] !== str[right]) {
      return false;
    }
    left++;
    right--;
  }
  return true;
}

3. 使用栈，将字符串的每个字符依次入栈，再依次出栈，判断出栈的字符是否和原字符串相等

function isPalindrome(str) {
  var stack = [];
  for (var i = 0; i < str.length; i++) {
    stack.push(str[i]);
  }
  var reversedStr = '';
  while (stack.length > 0) {
    reversedStr += stack.pop();
  }
  return str === reversedStr;
}