web实习三_JavaScript编程

编写 JavaScript 程序实现输出“九九乘法表”（左下三角形形式）。

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <script>
        for(var i=1;i<=9;i++){
            str='';
            for(var j=1;j<=i;j++){
                str+=j+"*"+i+"="+i*j+"\t";
            }
            console.log(str);
        }
    </script>
</body>
</html>

2.编写 JavaScript 程序，测试输入的数是否是素数。

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <script>
       var num=17;
       var flag=true;
       if(num>=0){
        if(num==1||num==0){
            flag=false;
        }else if(flag==2)
            flag=true;           
       }else{
        for(var i=2;i<Math.sqrt(num);i++){
            if(num%i==0){
                flag=false;
                break;
            }
        }
       }

       console.log(flag);
    </script>
</body>
</html>

3.编写函数 isAnagram(str1,str2)用来检查两个字符串是否互为变位词。变位词指不计顺序的情况下两个单词包含完全相同的字母，不多不少。比如“silent”和“listen”互为变位词。

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=<device-width>, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <script>
        function isAnagram(str1, str2) {    
             if (str1.length !== str2.length) {
                  return false;
             }
              str1 = str1.split('');
              //将str1转为数组！
            for (var i = 0; i < str2.length; i++) {
                 var index = str1.indexOf(str2[i]);
                if (index === -1) {
                     return false;
                } else {
                    str1.splice(index, 1);
                 }
             }
              return str1.length === 0;
        }
        console.log(isAnagram("listen", "slient"));

    </script>
</body>
</html>

4.编写函数 checkPalindrome(str)判断字符串 str 是否为回文字符串。如果一个字符串从前往后读和从后往前读是一样的，那么它就是一个回文字符串。例如，“mom”、“dad”以及“noon”都是回文字符串。如，checkPalinadrome("mom")结果为 true。

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <script>
        function checkPalindrome(str){
            var flag=true;
            str=str.split('');
            for(var i=0;i<str.length;i++){
                if(i==str.length-1-i)
                    break;

                if(str[i]!=str[str.length-i-1]){
                    flag=false;
                    break;
                }
            }
            return flag;
        }

        console.log(checkPalindrome("mom"));
    </script>
</body>
</html>

5. 编写 Javascript 程序,找出符合条件的数。

(1)页面的标题是“找出符合条件的数”

(2)页面内容：3 号标题显示“找出 1000 ~ 9999 之间能够被 17和 13 同时整除的整数、个数、累加和”。

(2)输出格式：每行 10 个整数。

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>找出符合条件的数</title>
</head>
<body>
    <h3>找出 1000 ~ 9999 之间能够被 17和 13 同时整除的整数、个数、累加和</h3>
</body>
<script>
    let cnt=0;
    let sum=0;
    document.write("区间中符合条件的数有：<br />");
    for(let i=1000;i<=9999;i++){
        if(i%13==0&&i%17==0){
            document.write(i+" ");
            cnt++;
            sum+=i;
            if(cnt%10==0)
                document.write('<br />');
        }
    }
    document.write(`<br />区间中符合条件的数共有${cnt}个`);
    document.write(`<br/>累加和为${sum}<br/>`)
</script>
</html>

6.利用 Date 对象编写程序，判断并输出今天是开学的第几周，星期几。

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <script>
	function calculateWeekday(startDate) {

  const today = new Date();

  const timeDiff = today.getTime() - startDate.getTime();
  const totalDays = Math.ceil(timeDiff / (1000 * 3600 * 24));

  const weeks = Math.floor(totalDays / 7) + 1;

  const days = today.getDay();

  return `今天是开学后的第 ${weeks} 周，星期${days} `;
}

const startDate = new Date(2023, 8, 16); 

const result = calculateWeekday(startDate);
console.log(result);

    </script>
</body>
</html>

7. 设计一个网页，输入一串用英文逗号分隔的数字字符串。编写程序，输出找出该组数中的最大、最小值、和。并按从大到小排序后的输出结果（以逗号分隔）。

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>数字处理</title>
</head>
<body>

<label for="numbers">输入一串数字（用英文逗号分隔）：</label>
<input type="text" id="numbers">

<button onclick="processNumbers()">处理</button>

<p>最大值: <span id="maxValue"></span></p>
<p>最小值: <span id="minValue"></span></p>
<p>总和: <span id="sumValue"></span></p>
<p>排序结果: <span id="sortedResult"></span></p>

<script>
  function processNumbers() {
    const numbersInput = document.getElementById('numbers');
    const numbersArray = numbersInput.value.split(',').map(num => parseInt(num.trim(), 10));

    const maxValue = Math.max(...numbersArray);
    const minValue = Math.min(...numbersArray);
    const sumValue = numbersArray.reduce((acc, curr) => acc + curr, 0);
    const sortedResult = numbersArray.sort((a, b) => b - a).join(', ');

    document.getElementById('maxValue').innerText = maxValue;
    document.getElementById('minValue').innerText = minValue;
    document.getElementById('sumValue').innerText = sumValue;
    document.getElementById('sortedResult').innerText = sortedResult;
  }
</script>

</body>
</html>

8.要求用户在文本框中年份，点击判断按钮，用 alert 函数输出该年是否是闰年的结果。

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>判断闰年</title>
</head>
<body>

<input type="text"  name="txtYear" id="txtyear" >

<input type="button" value="判断" onclick="testLeapYear()">

<script>
  function testLeapYear(){
    // 获取用户输入的年份
    const yearInput = document.getElementById('txtyear');
    const year = parseInt(yearInput.value);

    // 判断是否为闰年
    const isLeapYear = (year % 4 === 0 && year % 100 !== 0) || (year % 400 === 0);

    // 显示结果
    const resultMessage = isLeapYear ? `${year}年是闰年！` : `${year}年不是闰年。`;
    alert(resultMessage);
  }
</script>

</body>
</html>

9.直接使用 Javascript 的计时器、DOM 模型操作，将当前目录下的 10 张图片循环显示在网页上。

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <img id="displayedImage" src="" alt="image">
  
    <script>
      let currentIndex = 1; 
      const totalImages = 10;
  
      function displayNextImage() {
        const imageElement = document.getElementById('displayedImage');
        const imagePath = `./image/image${currentIndex}.jpg`;
  
        imageElement.src = imagePath; 
  
        currentIndex = (currentIndex % totalImages) + 1; 
  
        setTimeout(displayNextImage, 2000); 
      }
  
     
      window.onload = function() {
        displayNextImage();
      };
    </script>
</body>
</html>

10.制作“随机密码生成”程序，完成如图 1 所示界面，JavaScript 编程实现“生成密码”的功能。密码长度为：1～16 位，密码数量：1～10 个。

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=<device-width>, initial-scale=1.0">
    <title>Document</title>
    <style>

   table {
      border-collapse: collapse;
      font-size: 12px;
      width: 400px;
      height: 350px;
    }

    td{
      border: 1px solid gray;
      padding: 8px; 
    }
    #bt{
        background-color:cyan;
        color: white;
        border: 0;
    }
    #paichutext{
       background-color:darkgray;
       border: 1px solid gray;
    }
    #otherchar{
        width: 45px;
        background-color: darkgrey;
        border: 1px solid gray;
    }
    </style>
</head>
<body>
    <table border="1" >
        <tr> 
            <td style="background-color:darkgray;">所用字符</td>
            <td colspan="3">
            <input type="checkbox" name="need" id="az">a-z
            <input type="checkbox" name="need" id="AZ">A-Z
            <input type="checkbox" name="need" id="09">0-9
            <input type="checkbox" name="need" id="oz">
            <input type="text" id="otherchar" value="!@#$%">
             </td>
        </tr>

        <tr>
            <td style="background-color:darkgray;">排除字符</td>
            <td colspan="3">
                <input type="checkbox" id="paichu"> 
                <input type="text"  id="paichutext" value="illo0O">
            </td>
        </tr>

        <tr>
            <td style="background-color:darkgray;">密码长度</td>
            <td>
                <select id="selen" >
                    <option value="len1">1</option>
                    <option value="len2">2</option>
                    <option value="len3">3</option>
                    <option value="len4">4</option>
                    <option value="len5">5</option>
                    <option value="len6">6</option>
                    <option value="len7">7</option>
                    <option value="len8">8</option>
                    <option value="len9">9</option>
                    <option value="len10">10</option>
                    <option value="len11">11</option>
                    <option value="len12">12</option>
                    <option value="len13">13</option>
                    <option value="len14">14</option>
                    <option value="len15">15</option>
                    <option value="len16">16</option>
                </select>
                位
            </td>
            <td style="background-color:darkgray;">密码数量</td>
            <td>
                <select id="secnt" >
                    <option value="op1">1</option>
                    <option value="op2">2</option>
                    <option value="op3">3</option>
                    <option value="op4">4</option>
                    <option value="op5">5</option>
                    <option value="op6">6</option>
                    <option value="op7">7</option>
                    <option value="op8">8</option>
                    <option value="op9">9</option>
                    <option value="op10">10</option>
                </select>
                个
            </td>
        </tr>
        <tr>
           <td colspan="4" align="center">
            <button id="bt" onclick="generatepasswd()">生成密码</button></td> 
        </tr>
        <tr>
           <td colspan="4" align="center" >
            <textarea id="textarea" style="height: 70px;">
            </textarea>
           </td> 
        </tr>
    </table>
    <script>
        function generatepasswd(){

            var len= document.getElementById("selen");
            var lenop=len.options[len.selectedIndex].text;
            var numlen=parseInt(lenop);

            var cnt= document.getElementById("secnt");
            var cntop=cnt.options[cnt.selectedIndex].text;
            var numcnt=parseInt(cntop);

            const lowercaseChars = 'abcdefghijklmnopqrstuvwxyz';
            const uppercaseChars = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ';
            const numberChars = '0123456789';
            const otherChars=document.getElementById("otherchar").value;
            const paichuChars=document.getElementById("paichutext").value;
            let allChars='';
            let passwd='';
            
            if(document.getElementById('az').checked){
                allChars+=lowercaseChars;
            }
            if(document.getElementById('AZ').checked){
                allChars+=uppercaseChars;
            }
            if(document.getElementById('09').checked){
                allChars+=numberChars;
            }
            if(document.getElementById('oz').checked){
                allChars+=otherChars;
            }
            if(document.getElementById('paichu').checked){
                allChars= allChars.replace(new RegExp('[' + paichuChars + ']', 'g'), '');
            }
            
            console.log(otherChars);
            console.log(paichuChars);


            var val=document.getElementById("textarea");
            for(let i=0;i<numcnt;i++){
                passwd='';
                for (let j= 0; j< numlen;j++) {
                    const randomIndex = Math.floor(Math.random() * allChars.length);
                    passwd += allChars.charAt(randomIndex);
                }
                val.value += passwd+'\n';
            }
        }
    </script>
</body>
</html>

11. 使用 JavaScript 和 HTML 设计一个简单的整数四则运算测试程序(如图 2 所示)，要求实现以下功能：

（1）用户可以在页面上选择题目类型和题目数量。

（2）用户单击“开始答题”按钮来开始答题。

（3）页面上需要显示题目和用户的答案。

（4）单击“提交答案”按钮来提交答案，系统显示用户得分。

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
     #quiz-container {
      margin: 20px;
    }

    .question-container {
      margin-bottom: 10px;
      padding: 5px;
    }

    .correct {
      background-color: green;
    }

    .incorrect {
      background-color: red;
    }
    </style>
</head>
<body>
    <h2>整数四则运算测试</h2>
    <p>
        题目类型：
    <select id="question_type">
        <option value="add">加法</option>
        <option value="reduce">减法</option>
        <option value="mul">乘法</option>
        <option value="chu">除法</option>
    </select>
    </p>
    <p>
        题目数量：
        <input type="number" id="question_number" min="1">
    </p>
    <p>
        <button id="start" onclick="startQuiz()">开始答题</button>
        <button id="submit" onclick="submitAnswers()" >提交答案</button>
    </p>
    <div id="quiz"></div>
    <div id="score"></div>

    <script>
         let currentQuestion = 0;
        let score = 0;
        let questions = [];

        function startQuiz(){
            currentQuestion = 0;
            score = 0;
            questions = generateQuestions();

            showQuestions();
        };

        function generateQuestions(){
           
            questionType=document.getElementById('question_type').value;
            questionNumber=document.getElementById('question_number').value;
            const generatedQuestions = [];
            
            
          for (let i = 0; i < questionNumber; i++) {
            const num1 = Math.floor(Math.random() * 10);
            const num2 = Math.floor(Math.random() * 10);

            switch (questionType) {
             case 'add':
                 correctAnswer = num1 + num2;
                 generatedQuestions.push({
                    question: `${num1} + ${num2} = `,
                    correctAnswer: correctAnswer.toString(),
                    userAnswer: ''
                 });
              break;
             case 'reduce':
                 correctAnswer = num1 - num2;
                 generatedQuestions.push({
                    question: `${num1} - ${num2} = `,
                    correctAnswer: correctAnswer.toString(),
                    userAnswer: ''
                 });
              break; 
              case 'mul':
                 correctAnswer = num1 * num2;
                 generatedQuestions.push({
                    question: `${num1} * ${num2} = `,
                    correctAnswer: correctAnswer.toString(),
                    userAnswer: ''
                 });
              break; 
              case 'chu':
                 correctAnswer = num1 /num2;
                 generatedQuestions.push({
                    question: `${num1} / ${num2} = `,
                    correctAnswer: correctAnswer.toString(),
                    userAnswer: ''
                 });
              break; 
            }
         }
         return generatedQuestions;
        }
        function showQuestions() {
         const quizContainer = document.getElementById('quiz');
         quizContainer.innerHTML = '';

         for (let i = 0; i < questions.length; i++) {
            const questionContainer = document.createElement('div');
            questionContainer.className = 'question-container';
            questionContainer.innerHTML = `${questions[i].question} <input type="text" id="answer${i}" onchange="updateUserAnswer(${i})">`;
            quizContainer.appendChild(questionContainer);
             }
        }
        function updateUserAnswer(index) {
         questions[index].userAnswer = document.getElementById(`answer${index}`).value;
        }

        function submitAnswers() {
    for (let i = 0; i < questions.length; i++) {
      const questionContainer = document.querySelector(`#quiz .question-container:nth-child(${i + 1})`);

      if (questions[i].userAnswer === questions[i].correctAnswer) {
        questionContainer.classList.add('correct');
        score++;
      } else {
        questionContainer.classList.add('incorrect');
      }
    }

    showScore();
  }

  function showScore() {
    const scoreContainer = document.getElementById('score');
    scoreContainer.innerHTML = `得分: ${score} / ${questions.length}`;
  }

    </script>
</body>
</html>