js基础-day1-2

2026-07-01 16:04:43 +08:00
parent fdb0253799
commit c3f10f72a3
8 changed files with 116 additions and 2 deletions
@@ -0,0 +1,15 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <title>数组体验</title>
+</head>
+<body>
+<script>
+    // 声明数组
+    let  arr = [10,20,30,40,10]
+    //使用数组 数组名[索引]
+    document.writeln(arr[1])
+</script>
+</body>
+</html>
@@ -0,0 +1,17 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <title>Title</title>
+</head>
+<body>
+<script>
+    let num1 = 10,num2 = 20
+    let temp
+    temp = num1
+    num1 = num2
+    num2 = temp
+    document.writeln(`num1 = ${num1},num2 = ${num2}`)
+</script>
+</body>
+</html>
@@ -0,0 +1,17 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <title>Title</title>
+</head>
+<body>
+<script>
+    // 规则：
+    //     不能用关键字只能用下划线，数字，字母，$组成，且数字不能开头
+    //     字母严格区分大小写
+    // 规范：
+    //     1.见名之意
+    //     2.遵守小驼峰命名法
+</script>
+</body>
+</html>
@@ -2,9 +2,12 @@
 <html lang="en">
 <head>
    <meta charset="UTF-8">
-    <title>Title</title>
+    <title>常量</title>
 </head>
 <body>
-
+<script>
+    const PI = 3.14
+    console.log(PI)
+</script>
 </body>
 </html>
@@ -0,0 +1,14 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <title>Title</title>
+</head>
+<body>
+    <script>
+        let  r = prompt("请输入半径")
+        const PI = 3.14
+        document.writeln(`半径为${r}的圆，面积为${PI*r*r}`)
+    </script>
+</body>
+</html>
@@ -0,0 +1,14 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <title>计算两者的和，打印到页面中</title>
+</head>
+<body>
+<script>
+    let num1 = prompt("输入第一个数字")
+    let num2 = prompt("输入第二个数字")
+    alert(`数字${num1}和数字${num2}的和是：${Number(num1)+Number(num2)}`)
+</script>
+</body>
+</html>
@@ -0,0 +1,14 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <title>数组取值案例</title>
+</head>
+<body>
+<script>
+    let atr = ['星期一','星期二','星期三','星期四','星期五','星期六','星期日']
+    document.writeln(atr[6])
+    document.writeln(atr[atr.length -1])
+</script>
+</body>
+</html>
@@ -0,0 +1,20 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <title>输出用户信息</title>
+</head>
+<body>
+<script>
+    // let uname = prompt("请输入你的姓名：")
+    // let age = prompt("请输入你的年龄:")
+    // let gender = prompt("请输入你的性别：")
+    // document.writeln(`姓名：${uname},性别：${gender},年龄：${age}`)
+    // typeof age
+    // document.writeln('3' * 5)
+    let str = '123'
+    document.writeln(typeof str)
+    document.writeln(typeof Number(str))
+</script>
+</body>
+</html>