js基础-练习三

九九乘法表：

<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=sc, initial-scale=1.0">
    <title>九九乘法表</title>
    <style>
        span {
            height: 30px;
            width: 80px;
            display: inline-block;
            border: 1px solid #ccc;
            /* padding: 1px 2px; */
            margin: 2px;
            text-align: center;
            line-height: 30px;
            box-shadow: 2px 1px 1px rgba(56, 56, 127, 0.3);
        }
    </style>
</head>

<body>
    <h3>九九乘法表</h3>


    <script>
        for (let i = 1; i <= 9; i++) {
            for (let j = 1; j <= i; j++) {
                document.write(`<span>${j}*${i}=${i * j} </span>`)
            }
            document.write('<br>')
        }
    </script>
</body>

</html>

运行结果：

根据数据生成柱形图：

<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>综合案例-根据数据生成柱形图素材</title>
    <style>
        * {
            margin: 0;
            padding: 0;
        }

        .box {
            display: flex;
            width: 700px;
            height: 300px;
            border-left: 1px solid pink;
            border-bottom: 1px solid pink;
            margin: 50px auto;
            justify-content: space-around;
            align-items: flex-end;
            text-align: center;
        }

        .box>div {
            display: flex;
            width: 50px;
            background-color: pink;
            flex-direction: column;
            justify-content: space-between;
        }

        .box div span {

            margin-top: -20px;
        }

        .box div h4 {
            margin-bottom: -35px;
            width: 70px;
            margin-left: -10px;
        }
    </style>
</head>

<body>
    <script>
        let arr = []
        for (let i = 1; i <= 4; i++) {
            arr.push(prompt(`请输入第${i}季度的数据`))
        }
        document.write(`<div class="box">`)
        for (i = 0; i < arr.length; i++) {
            document.write(`
        <div style="height: ${arr[i]}px;">
        <span>${arr[i]}</span>
        <h4>第${i}季度</h4>
        </div>`)
        }
        document.write(`</div>`)


    </script>
</body>

</html>

运行结果：

写一个程序，要求如下（★★）

需求1：让用户输入五个有效年龄（0-100之间），放入数组中
- 必须输入五个有效年龄年龄，如果是无效年龄，则不能放入数组中
需求2：打印出所有成年人的年龄 (数组筛选)
需求3：打印出所有人总年龄（累加）
需求4：打印出所有人的平均年龄（累加）
需求5：打印出最大年龄和最小年龄（最大值）

<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>练习题一</title>
</head>

<body>
    <script>
        let arr = []
        while (arr.length < 5) {
            let age = +prompt(`请您输入五个有效年龄（0-100之间）`)
            if (age >= 0 && age <= 100) {
                arr.push(age)
            }
        }
        document.write(`${arr}\<br>`);
        for (let i = 0; i < arr.length; i++) {
            if (arr[i] >= 18) {
                document.write(`已经成人的年纪是${arr[i]}岁\<br>`)
            }
        }
        let sum = 0
        for (let i = 0; i < arr.length; i++) {
            sum += arr[i]
        }
        document.write(`所有人的总年龄为${sum}\岁<br>`)
        document.write(`所有人的平均年龄为${sum / arr.length}岁\<br>`)
        let max = arr[0]
        let min = arr[0]
        for (let i = 0; i < arr.length - 1; i++) {
            if (arr[i] < arr[i + 1]) {
                max = arr[i + 1]
            }
            if (arr[i] > arr[i + 1]) {
                mIn = arr[i + 1]
            }
        }
        document.write(`最大年龄为${max}岁\<br>`)
        document.write(`最小年龄为${min}岁\<br>`)
    </script>
</body>

</html>

运行结果（忽略输入过程）：

找出数组中元素为10的下标，有则打印该下标，没有则打印-1

例如: [88,20,10,100,50] 打印 2

例如: [88,20,30,100,50] 打印-1

<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>练习题二</title>
</head>

<body>
    <script>
        let arr = [88, 20, 10, 100, 50]
        let re = -1
        for (let i = 0; i < arr.length; i++) {
            if (arr[i] === 10) {
                re = i
                break
            }
        }
        document.write(re)
    </script>
</body>

</html>

核心练习：

需求：

根据用户输入的个数，页面可以渲染对应王者荣耀永雄的个数

效果如下：

<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>核心练习</title>
    <style>
        * {
            margin: 0;
            padding: 0;
        }

        li {
            list-style: none;
        }

        .box {
            display: flex;
            flex-wrap: wrap;
            width: 540px;
            margin: 20px auto;
        }



        .box li {
            width: 100px;
            height: 100px;
            margin: 0 10px 10px 0;
        }

        .box li:nth-child(5n+1) {
            margin-right: 0;
        }

        .box li img {
            width: 100%;
            height: 100%;
            border: 2px solid #258DF2;
            border-radius: 10px 0 10px 0;
        }
    </style>
</head>

<body>
    <ul class="box">

        <script>
            let arr = [
                './核心练习作业素材/images/1.webp',
                './核心练习作业素材/images/2.webp',
                './核心练习作业素材/images/3.webp',
                './核心练习作业素材/images/4.webp',
                './核心练习作业素材/images/5.webp',
                './核心练习作业素材/images/6.webp',
                './核心练习作业素材/images/7.webp',
                './核心练习作业素材/images/8.webp',
                './核心练习作业素材/images/9.webp',
                './核心练习作业素材/images/10.webp',
                './核心练习作业素材/images/11.webp',
                './核心练习作业素材/images/12.webp',
                './核心练习作业素材/images/13.webp',
                './核心练习作业素材/images/14.webp',
                './核心练习作业素材/images/15.webp',
                './核心练习作业素材/images/16.webp',
                './核心练习作业素材/images/17.webp',
                './核心练习作业素材/images/18.webp',
                './核心练习作业素材/images/19.webp',
                './核心练习作业素材/images/20.webp'
            ]
            let num = +prompt('请输入显示的英雄个数1~20之间：')
            for (let i = 0; i < num; i++) {
                document.write(`
                <li>
            <img src="${arr[i]}" alt="">
                </li>
                `)
            }
        </script>
    </ul>
</body>

</html>

运行结果：