JS第四课(运算符)（二）

 <script>
    // 第一个作业
    confirm("开始作业的介绍");
    var Name = prompt("请输入用户的姓名哦");
    var Age = prompt("请输入用户的年龄");
    var Sex = prompt("请输入用户的性别");
    console.log(Name, Age, Sex);
    document.write("<h1>" + Name, Age, Sex + "</h1>")
    // 第二个作业
    // 方式一
    var str = "Good Byte";
    // 方式二
    var str1 = "北极市";
    // 方式三
    var str2 = `2022我的姓名是:${str1}在那个\r注册城市${str1},少年游戏\\我的姓\n名是:${str1}在那个
城\b市$
    {str1},少年游戏\t我的姓名是:${str1}在那个城市${str1},少年游戏`;
    // 字符串的注意事项
    var sdr = "外双内单'内双外单'kk\"泛内容释放\"Let is G";
    console.log(str);
    console.log(str1);
    console.log(str2);
    console.log(sdr);
    console.log(sdr.length);
    // 第三个作业
    var aaa = alert(isNaN(NaN))
    var aaa1 = alert(isNaN(12))
    var aaa2 = alert(isNaN(100))
    var aaa3 = alert(isNaN("我是谁"))
    var aaa4 = alert(isNaN("back"))
    console.log(aaa, aaa2, aaa3, aaa4)
    // 第四个作业
    var count = "我们的班级来了45新同志"
    console.log(typeof count);
    count = 10;
    console.log(typeof count);
    var flag = true;
    console.log(typeof flag);
    var a1 = undefined;
    console.log(typeof a1);
    var a2 = null;
    console.log(typeof a2);
    var a3 = []
    console.log(typeof a3);
    var a4 = {}
    console.log(typeof a4);
    function aayt() { }
    console.log(typeof aayt)
</script>

    <!-- 键的取值 -->
    <script>
        console.log("键的取值")
        var a, b, c;
        a = b = c = 2 + 2;
        console.log(a, b, c);
    </script>

    <!-- 练习题 -->
    <script>
        console.log(" 练习题")
        //练习题一
        var a = 456;
        ++a;
        console.log(a);
        //    练习二
        var b = ++a + 34;
        console.log(b);
        //    练习四
        var c = 122;
        c++;
        var d = c++ - 54;
        console.log(d);
        //    练习六
        var e = 123;
        var f = e++ + ++e;
        console.log(e);
    </script>
    <!-- 综合回顾 -->
    <script>
        console.log("综合回顾")
        //    浮点数2
        var num = console.log(0.3 + 0.4);
        console.log(0.3 * 1000);
        console.log(num == 0.7);
        console.log("浮点数")
        //    自++ 自--
        var sd = 10;
        ++sd; //age=age+1
        console.log(sd);
        var sds = 100;
        --sds; //age=age+1
        console.log(sds);
        //后置++运算符
        var sd = 234;
        sd++;
        console.log(sd);
        var p = 345;
        console.log(++p + 456);
        //后置--运算符
        var sdq = 234;
        sdq--;
        console.log(sdq);
        //定义一个变量++破+456
        var p = 345;
        console.log(++p + 456);
        console.log("++--")
        //比较运算符关系运算符·
        console.log(2 >= 4);
        console.log(2 <= 4);
        console.log(2 == 4 / 2);
        console.log(2 != 4);
        console.log(456 == 789);
        console.log(2 != 4);
        console.log(4 === 4);
        console.log("比较运算符关系运算符")
        //逻辑运算符 boolean 与或非
        console.log(3 > 5 && 3 > 2);
        console.log(32 > 53 && 32 < 2);
        console.log(3 > 5 || 3 > 2);
        console.log(true);
        //逻辑短路
        console.log(123 && 4567);
        console.log(0 && 4567);
        console.log(0 && 1 + 2 && 456 * 89889);
        //逻辑或短路
        console.log(123 || 456);
    </script>
    <!--2022年10月13号的信息内容 -->
    <script>
        var num = prompt("请用户输入的三位数");
        ge = num % 10,
            shi = Math.floor(num / 100) % 10,
            bai = Math.floor(num / 100) % 10,
            sum = ge + shi + bai;
        alert('各数位的和为:' + sum)
    </script>
    <script>
        var l = prompt("请用户输入长度");
        var p = prompt("请用户输入宽度");
        confirm("面积")
        alert(l * p)
        confirm("周长")
        alert(2 * (l + p))
    </script>
    <script>
        var pp = 89;
        var pp = 89 % 24;
        console.log(pp)
        alert(pp)
        var pp = 89 / 24;
        console.log(pp)
        alert(pp)
    </script>
    <script>
        var tyu = prompt("请输入四位的数值");
        ge = tyu % 10,
            shi = parseInt(tyu / 10) % 10,
            bai = parseInt(tyu % 100) / 100,
            qian = parseInt(tyu / 1000)
        console.log(ge)
        console.log(shi)
        console.log(bai)
        console.log(qian)
    </script>
    <script>
    </script>
    <script>
        //作业二
        var date = new Date()
        date = date.getDate();
        var day = prompt("输入内容") * 1
        var week = (day % 7 + date) % 7
        if (week == 0) {
            week == 7;
            console.log(week)
        }
    </script>

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>运算符</title>
</head>
<body>
<h1>算数运算符: 2:2+2 2-2 2*2 2/2 2%2</h1><br>
<h1>前置和后置的++与--</h1>
<h1>逻辑运算符 boolean 与或非</h1>
<script>
    console.log(2+2);
    console.log(2/2);
    console.log(2*2);
    console.log(2-2);
    console.log(8%2);
//    浮点数2
    var num =console.log(0.3+0.4);
    console.log(0.3*1000);
    console.log(num==0.7);
//    自++ 自--
    var sd=10;
    ++sd; //age=age+1
    console.log(sd);
    var sds=100;
    --sds; //age=age+1
    console.log(sds);
    //后置++运算符
    var sd=234;
    sd++;
    console.log(sd);
    var p=345;
    console.log(++p+456);
    //后置--运算符
    var sdq=234;
    sdq--;
    console.log(sdq);
    //定义一个变量++破+456
    var p=345;
    console.log(++p+456);
    //练习题一
    var a=456;
    ++a;
    console.log(a);
//    练习二
    var b=++a+34;
    console.log(b);
//    练习四
    var c =122;
    c++;
    var d=c++ -54;
    console.log(d);
    //    练习六
    var e=123;
    var f= e++ + ++e;
    console.log(e);
//比较运算符关系运算符·
    console.log(2>=4);
    console.log(2<=4);
    console.log(2==4/2);
    console.log(2!=4);
    console.log(456==789);
    console.log(2!=4);
    console.log(4===4);
    //逻辑运算符 boolean 与或非
    console.log(3>5&& 3>2);
    console.log(32>53&& 32<2);
    console.log(3>5|| 3>2);
    console.log(true);
    //逻辑短路
    console.log(123 &&4567);
    console.log(0 &&4567);
    console.log(0&&1+2&&456*89889);
    //逻辑或短路
    console.log(123||456);
</script>
</body>
</html>