【JavaScript脚本】——T1基本语法

<script></script>

<script>
    document.write("<h1>Hello World!</h1>");
</script>

<script src="demo.js"></script>

var x=125;

var msg="Hello World";

console.log(x);
console.log(msg);

<script>
    var x;
    document.write(typeof(x) + "<br/>");
    var y = '';
    document.write(typeof(y) + "<br/>");
    var b = true;
    document.write(typeof(b) + "<br/>");
    var n = 520;
    document.write(typeof(n) + "<br/>");
    var s = "幸福安康";
    document.write(typeof(s) + "<br/>");
</script>

<script>
    var sex = 11;
    if (sex == 11) {
        document.write("男性");
    } else {
        document.write("女性");
    }
</script>

<script>
    var month = 12;
    if (month == 12 || month == 1 || month == 2) {
        document.write("冬季");
    } else if (month == 3 || month == 4 || month == 5) {
        document.write("春季");
    } else if (month == 6 || month == 7 || month == 8) {
        document.write("夏季");
    } else if (month == 9 || month == 10 || month == 11) {
        document.write("秋季");
    } else {
        document.write("不是地球公转周期");
    }
</script>

<script>
    var key=1;
    switch (key) {
        case 1:document.write("星期一");break;
        case 2:document.write("星期二");break;
        case 3:document.write("星期三");break;
        case 4:document.write("星期四");break;
        case 5:document.write("星期五");break;
        case 6:document.write("星期六");break;
        case 7:document.write("星期七");break;
    
        default:document.write("星期八?");break;
    }
</script>

<script>
    var i=1;
    var sum=0;
    while (i<=100) {
        sum+=i;
        i++;
    }
    document.write("1++100的结果是："+sum);
</script>

<script>
    var i = 1;
    var sum = 0;
    do {
        sum += i;
        i++;
    } while (i <= 100);
    document.write("1++100的结果是：" + sum);
</script>

<script>
    var sum = 0;
    for (var i = 0; i < 101; i++) {
        sum+=i;
    }
    document.write("for循环1++100的结果是：" + sum);
</script>

<script>
    for (var i = 0; i < 10; i++) {
        if (i % 2 == 0) {
            document.write(i);
            continue;
        }
        if (i == 7) {
            document.write(i + "停止");
            break;
        }
        document.write("数字" + i);
    }
</script>

<script>
    for (var i = 1; i < 10; i++) {
        for (var j = 1; j <= i; j++) {
            document.write(j + "*" + i + "=" + (j * i) + "&nbsp;");
        }
        document.write("<br/>");
    }
</script>