对JavaScript一无所知~离精通只差一步之遥的人

2023-10-13 23:09

本文主要是介绍对JavaScript一无所知~离精通只差一步之遥的人,希望对大家解决编程问题提供一定的参考价值,需要的开发者们随着小编来一起学习吧!

 

适合阅读范围:对JavaScript一无所知~离精通只差一步之遥的人

基础知识:HTML

JavaScript就这么回事1:基础知识

1 创建脚本块

1: <script language=”JavaScript”>

2: JavaScript code goes here

3: </script>

2 隐藏脚本代码

1: <script language=”JavaScript”>

2: <!--

3: document.write(“Hello”);

4: // -->

5: </script>

在不支持JavaScript的浏览器中将不执行相关代码

3 浏览器不支持的时候显示

1: <noscript>

2: Hello to the non-JavaScript browser.

3: </noscript>

4 链接外部脚本文件

1: <script language=”JavaScript” src="/”filename.js"”></script>

5 注释脚本

1: // This is a comment

2: document.write(“Hello”); // This is a comment

3: /*

4: All of this

5: is a comment

6: */

6 输出到浏览器

1: document.write(“<strong>Hello</strong>”);

7 定义变量

1: var myVariable = “some value”;

8 字符串相加

1: var myString = “String1” + “String2”;

9 字符串搜索

1: <script language=”JavaScript”>

2: <!--

3: var myVariable = “Hello there”;

4: var therePlace = myVariable.search(“there”);

5: document.write(therePlace);

6: // -->

7: </script>

10 字符串替换

1: thisVar.replace(“Monday”,”Friday”);

11 格式化字串

1: <script language=”JavaScript”>

2: <!--

3: var myVariable = “Hello there”;

4: document.write(myVariable.big() + “<br>”);

5: document.write(myVariable.blink() + “<br>”);

6: document.write(myVariable.bold() + “<br>”);

7: document.write(myVariable.fixed() + “<br>”);

8: document.write(myVariable.fontcolor(“red”) + “<br>”);

9: document.write(myVariable.fontsize(“18pt”) + “<br>”);

10: document.write(myVariable.italics() + “<br>”);

11: document.write(myVariable.small() + “<br>”);

12: document.write(myVariable.strike() + “<br>”);

13: document.write(myVariable.sub() + “<br>”);

14: document.write(myVariable.sup() + “<br>”);

15: document.write(myVariable.toLowerCase() + “<br>”);

16: document.write(myVariable.toUpperCase() + “<br>”);

17:

18: var firstString = “My String”;

19: var finalString = firstString.bold().toLowerCase().fontcolor(“red”);

20: // -->

21: </script>

12 创建数组

1: <script language=”JavaScript”>

2: <!--

3: var myArray = new Array(5);

4: myArray[0] = “First Entry”;

5: myArray[1] = “Second Entry”;

6: myArray[2] = “Third Entry”;

7: myArray[3] = “Fourth Entry”;

8: myArray[4] = “Fifth Entry”;

9: var anotherArray = new Array(“First Entry”,”Second Entry”,”Third Entry”,”Fourth Entry”,”Fifth Entry”);

10: // -->

11: </script>

13 数组排序

1: <script language=”JavaScript”>

2: <!--

3: var myArray = new Array(5);

4: myArray[0] = “z”;

5: myArray[1] = “c”;

6: myArray[2] = “d”;

7: myArray[3] = “a”;

8: myArray[4] = “q”;

9: document.write(myArray.sort());

10: // -->

11: </script>

14 分割字符串

1: <script language=”JavaScript”>

2: <!--

3: var myVariable = “a,b,c,d”;

4: var stringArray = myVariable.split(“,”);

5: document.write(stringArray[0]);

6: document.write(stringArray[1]);

7: document.write(stringArray[2]);

8: document.write(stringArray[3]);

9: // -->

10: </script>

15 弹出警告信息

1: <script language=”JavaScript”>

2: <!--

3: window.alert(“Hello”);

4: // -->

5: </script>

16 弹出确认框

1: <script language=”JavaScript”>

2: <!--

3: var result = window.confirm(“Click OK to continue”);

4: // -->

5: </script>

17 定义函数

1: <script language=”JavaScript”>

2: <!--

3: function multiple(number1,number2) {

4: var result = number1 * number2;

5: return result;

6: }

7: // -->

8: </script>

18 调用JS函数

1: <a href=”#” onClick=”functionName()”>Link text</a>

2: <a href="/”javascript:functionName"()”>Link text</a>

19 在页面加载完成后执行函数

1: <body onLoad=”functionName();”>

2: Body of the page

3: </body>

20 条件判断

1: <script>

2: <!--

3: var userChoice = window.confirm(“Choose OK or Cancel”);

4: var result = (userChoice == true) ? “OK” : “Cancel”;

5: document.write(result);

6: // -->

7: </script>

21 指定次数循环

1: <script>

2: <!--

3: var myArray = new Array(3);

4: myArray[0] = “Item 0”;

5: myArray[1] = “Item 1”;

6: myArray[2] = “Item 2”;

7: for (i = 0; i < myArray.length; i++) {

8: document.write(myArray + “<br>”);

9: }

10: // -->

11: </script>

22 设定将来执行

1: <script>

2: <!--

3: function hello() {

4: window.alert(“Hello”);

5: }

6: window.setTimeout(“hello()”,5000);

7: // -->

8: </script>

23 定时执行函数

1: <script>

2: <!--

3: function hello() {

4: window.alert(“Hello”);

5: window.setTimeout(“hello()”,5000);

6: }

7: window.setTimeout(“hello()”,5000);

8: // -->

9: </script>

24 取消定时执行

1: <script>

2: <!--

3: function hello() {

4: window.alert(“Hello”);

5: }

6: var myTimeout = window.setTimeout(“hello()”,5000);

7: window.clearTimeout(myTimeout);

8: // -->

9: </script>

25 在页面卸载时候执行函数

1: <body onUnload=”functionName();”>

2: Body of the page

3: </body>

JavaScript就这么回事2:浏览器输出

26 访问document对象

1: <script language=”JavaScript”>

2: var myURL = document.URL;

3: window.alert(myURL);

4: </script>

27 动态输出HTML

1: <script language=”JavaScript”>

2: document.write(“<p>Here’s some information about this document:</p>”);

3: document.write(“<ul>”);

4: document.write(“<li>Referring Document: “ + document.referrer + “</li>”);

5: document.write(“<li>Domain: “ + document.domain + “</li>”);

6: document.write(“<li>URL: “ + document.URL + “</li>”);

7: document.write(“</ul>”);

8: </script>

28 输出换行

1: document.writeln(“<strong>a</strong>”);

2: document.writeln(“b”);

29 输出日期

1: <script language=”JavaScript”>

2: var thisDate = new Date();

3: document.write(thisDate.toString());

4: </script>

30 指定日期的时区

1: <script language=”JavaScript”>

2: var myOffset = -2;

3: var currentDate = new Date();

4: var userOffset = currentDate.getTimezoneOffset()/60;

5: var timeZoneDifference = userOffset - myOffset;

6: currentDate.setHours(currentDate.getHours() + timeZoneDifference);

7: document.write(“The time and date in Central Europe is: “ + currentDate.toLocaleString());

8: </script>

31 设置日期输出格式

1: <script language=”JavaScript”>

2: var thisDate = new Date();

3: var thisTimeString = thisDate.getHours() + “:” + thisDate.getMinutes();

4: var thisDateString = thisDate.getFullYear() + “/” + thisDate.getMonth() + “/” + thisDate.getDate();

5: document.write(thisTimeString + “ on “ + thisDateString);

6: </script>

32 读取URL参数

1: <script language=”JavaScript”>

2: var urlParts = document.URL.split(“?”);

3: var parameterParts = urlParts[1].split(“&”);

4: for (i = 0; i < parameterParts.length; i++) {

5: var pairParts = parameterParts.split(“=”);

6: var pairName = pairParts[0];

7: var pairValue = pairParts[1];

8: document.write(pairName + “ :“ +pairValue );

9: }

10: </script>

你还以为HTML是无状态的么?

33 打开一个新的document对象

1: <script language=”JavaScript”>

2: function newDocument() {

3: document.open();

4: document.write(“<p>This is a New Document.</p>”);

5: document.close();

6: }

7: </script>

34 页面跳转

1: <script language=”JavaScript”>

2: window.location = “http://www.liu21st.com/”;

3: </script>

35 添加网页加载进度窗口

1: <html>

2: <head>

3: <script language='javaScript'>

4: var placeHolder = window.open('holder.html','placeholder','width=200,height=200');

5: </script>

6: <title>The Main Page</title>

7: </head>

8: <body onLoad='placeHolder.close()'>

9: <p>This is the main page</p>

10: </body>

11: </html>

JavaScript就这么回事3:图像

36 读取图像属性

1: <img src="/”image1.jpg"” name=”myImage”>

2: <a href=”# ” onClick=”window.alert(document.myImage.width)”>Width</a>

3:

37 动态加载图像

1: <script language=”JavaScript”>

2: myImage = new Image;

3: myImage.src = “Tellers1.jpg”;

4: </script>

38 简单的图像替换

1: <script language=”JavaScript”>

2: rollImage = new Image;

3: rollImage.src = “rollImage1.jpg”;

4: defaultImage = new Image;

5: defaultImage.src = “image1.jpg”;

6: </script>

7: <a href="/”myUrl"” onMouseOver=”document.myImage.src = rollImage.src;”

8: onMouseOut=”document.myImage.src = defaultImage.src;”>

9: <img src="/”image1.jpg"” name=”myImage” width=100 height=100 border=0>

39 随机显示图像

1: <script language=”JavaScript”>

2: var imageList = new Array;

3: imageList[0] = “image1.jpg”;

4: imageList[1] = “image2.jpg”;

5: imageList[2] = “image3.jpg”;

6: imageList[3] = “image4.jpg”;

7: var imageChoice = Math.floor(Math.random() * imageList.length);

8: document.write(‘<img src=”’ + imageList[imageChoice] + ‘“>’);

9: </script>

40 函数实现的图像替换

1: <script language=”JavaScript”>

2: var source = 0;

3: var replacement = 1;

4: function createRollOver(originalImage,replacementImage) {

5: var imageArray = new Array;

6: imageArray[source] = new Image;

7: imageArray[source].src = originalImage;

8: imageArray[replacement] = new Image;

9: imageArray[replacement].src = replacementImage;

10: return imageArray;

11: }

12: var rollImage1 = createRollOver(“image1.jpg”,”rollImage1.jpg”);

13: </script>

14: <a href=”#” onMouseOver=”document.myImage1.src = rollImage1[replacement].src;”

15: onMouseOut=”document.myImage1.src = rollImage1[source].src;”>

16: <img src="/”image1.jpg"” width=100 name=”myImage1” border=0>

17: </a>

41 创建幻灯片

1: <script language=”JavaScript”>

2: var imageList = new Array;

3: imageList[0] = new Image;

4: imageList[0].src = “image1.jpg”;

5: imageList[1] = new Image;

6: imageList[1].src = “image2.jpg”;

7: imageList[2] = new Image;

8: imageList[2].src = “image3.jpg”;

9: imageList[3] = new Image;

10: imageList[3].src = “image4.jpg”;

11: function slideShow(imageNumber) {

12: document.slideShow.src = imageList[imageNumber].src;

13: imageNumber += 1;

14: if (imageNumber < imageList.length) {

15: window.setTimeout(“slideShow(“ + imageNumber + “)”,3000);

16: }

17: }

18: </script>

19: </head>

20: <body onLoad=”slideShow(0)”>

21: <img src="/”image1.jpg"” width=100 name=”slideShow”>

42 随机广告图片

1: <script language=”JavaScript”>

2: var imageList = new Array;

3: imageList[0] = “image1.jpg”;

4: imageList[1] = “image2.jpg”;

5: imageList[2] = “image3.jpg”;

6: imageList[3] = “image4.jpg”;

7: var urlList = new Array;

8: urlList[0] = “http://some.host/”;

9: urlList[1] = “http://another.host/”;

10: urlList[2] = “http://somewhere.else/”;

11: urlList[3] = “http://right.here/”;

12: var imageChoice = Math.floor(Math.random() * imageList.length);

13: document.write(‘<a href=”’ + urlList[imageChoice] + ‘“><img src=”’ + imageList[imageChoice] + ‘“></a>’);

14: </script>

JavaScript就这么回事4:表单

还是先继续写完JS就这么回事系列吧~

43 表单构成

1: <form method=”post” action=”target.html” name=”thisForm”>

2: <input type=”text” name=”myText”>

3: <select name=”mySelect”>

4: <option value=”1”>First Choice</option>

5: <option value=”2”>Second Choice</option>

6: </select>

7: <br>

8: <input type=”submit” value=”Submit Me”>

9: </form>

44 访问表单中的文本框内容

1: <form name=”myForm”>

2: <input type=”text” name=”myText”>

3: </form>

4: <a href='#' onClick='window.alert(document.myForm.myText.value);'>Check Text Field</a>

45 动态复制文本框内容

1: <form name=”myForm”>

2: Enter some Text: <input type=”text” name=”myText”><br>

3: Copy Text: <input type=”text” name=”copyText”>

4: </form>

5: <a href=”#” onClick=”document.myForm.copyText.value =

6: document.myForm.myText.value;”>Copy Text Field</a>

46 侦测文本框的变化

1: <form name=”myForm”>

2: Enter some Text: <input type=”text” name=”myText” onChange=”alert(this.value);”>

3: </form>

47 访问选中的Select

1: <form name=”myForm”>

2: <select name=”mySelect”>

3: <option value=”First Choice”>1</option>

4: <option value=”Second Choice”>2</option>

5: <option value=”Third Choice”>3</option>

6: </select>

7: </form>

8: <a href='#' onClick='alert(document.myForm.mySelect.value);'>Check Selection List</a>

48 动态增加Select项

1: <form name=”myForm”>

2: <select name=”mySelect”>

3: <option value=”First Choice”>1</option>

4: <option value=”Second Choice”>2</option>

5: </select>

6: </form>

7: <script language=”JavaScript”>

8: document.myForm.mySelect.length++;

9: document.myForm.mySelect.options[document.myForm.mySelect.length - 1].text = “3”;

10: document.myForm.mySelect.options[document.myForm.mySelect.length - 1].value = “Third Choice”;

11: </script>

49 验证表单字段

1: <script language=”JavaScript”>

2: function checkField(field) {

3: if (field.value == “”) {

4: window.alert(“You must enter a value in the field”);

5: field.focus();

6: }

7: }

8: </script>

9: <form name=”myForm” action=”target.html”>

10: Text Field: <input type=”text” name=”myField”onBlur=”checkField(this)”>

11: <br><input type=”submit”>

12: </form>

50 验证Select项

1: function checkList(selection) {

2: if (selection.length == 0) {

3: window.alert(“You must make a selection from the list.”);

4: return false;

5: }

6: return true;

7: }

51 动态改变表单的action

1: <form name=”myForm” action=”login.html”>

2: Username: <input type=”text” name=”username”><br>

3: Password: <input type=”password” name=”password”><br>

4: <input type=”button” value=”Login” onClick=”this.form.submit();”>

5: <input type=”button” value=”Register” onClick=”this.form.action = ‘register.html’; this.form.submit();”>

6: <input type=”button” value=”Retrieve Password” onClick=”this.form.action = ‘password.html’; this.form.submit();”>

7: </form>

52 使用图像按钮

1: <form name=”myForm” action=”login.html”>

2: Username: <input type=”text” name=”username”><br>

3: Password: <input type=”password”name=”password”><br>

4: <input type=”image” src="/”login.gif"” value=”Login”>

5: </form>

6:

53 表单数据的加密

1: <SCRIPT LANGUAGE='JavaScript'>

2: <!--

3: function encrypt(item) {

4: var newItem = '';

5: for (i=0; i < item.length; i++) {

6: newItem += item.charCodeAt(i) + '.';

7: }

8: return newItem;

9: }

10: function encryptForm(myForm) {

11: for (i=0; i < myForm.elements.length; i++) {

12: myForm.elements.value = encrypt(myForm.elements.value);

13: }

14: }

15:

16: //-->

17: </SCRIPT>

18: <form name='myForm' onSubmit='encryptForm(this); window.alert(this.myField.value);'>

19: Enter Some Text: <input type=text name=myField><input type=submit>

20: </form>

JavaScript就这么回事5:窗口和框架

54 改变浏览器状态栏文字提示

1: <script language=”JavaScript”>

2: window.status = “A new status message”;

3: </script>

55 弹出确认提示框

1: <script language=”JavaScript”>

2: var userChoice = window.confirm(“Click OK or Cancel”);

3: if (userChoice) {

4: document.write(“You chose OK”);

5: } else {

6: document.write(“You chose Cancel”);

7: }

8: </script>

56 提示输入

1: <script language=”JavaScript”>

2: var userName = window.prompt(“Please Enter Your Name”,”Enter Your Name Here”);

3: document.write(“Your Name is “ + userName);

4: </script>

57 打开一个新窗口

1: //打开一个名称为myNewWindow的浏览器新窗口

2: <script language=”JavaScript”>

3: window.open(“http://www.liu21st.com/”,”myNewWindow”);

4: </script>

58 设置新窗口的大小

1: <script language=”JavaScript”>

2: window.open(“http://www.liu21st.com/”,”myNewWindow”,'height=300,width=300');

3: </script>

59 设置新窗口的位置

1: <script language=”JavaScript”>

2: window.open(“http://www.liu21st.com/”,”myNewWindow”,'height=300,width=300,left=200,screenX=200,top=100,screenY=100');

3: </script>

60 是否显示工具栏和滚动栏

1: <script language=”JavaScript”>

2: window.open(“http:

61 是否可以缩放新窗口的大小

1: <script language=”JavaScript”>

2: window.open('http://www.liu21st.com/' , 'myNewWindow', 'resizable=yes' );</script>

62 加载一个新的文档到当前窗口

1: <a href='#' onClick='document.location = '125a.html';' >Open New Document</a>

63 设置页面的滚动位置

1: <script language=”JavaScript”>

2: if (document.all) { //如果是IE浏览器则使用scrollTop属性

3: document.body.scrollTop = 200;

4: } else { //如果是NetScape浏览器则使用pageYOffset属性

5: window.pageYOffset = 200;

6: }</script>

64 在IE中打开全屏窗口

1: <a href='#' onClick=”window.open('http://www.juxta.com/','newWindow','fullScreen=yes');”>Open a full-screen window</a>

65 新窗口和父窗口的操作

1: <script language=”JavaScript”>

2: //定义新窗口

3: var newWindow = window.open(“128a.html”,”newWindow”);

4: newWindow.close(); //在父窗口中关闭打开的新窗口

5: </script>

6: 在新窗口中关闭父窗口

7: window.opener.close()

66 往新窗口中写内容

1: <script language=”JavaScript”>

2: var newWindow = window.open(“”,”newWindow”);

3: newWindow.document.open();

4: newWindow.document.write(“This is a new window”);

5: newWIndow.document.close();

6: </script>

67 加载页面到框架页面

1: <frameset cols=”50%,*”>

2: <frame name=”frame1” src="/”135a.html"”>

3: <frame name=”frame2” src="/”about:blank"”>

4: </frameset>

5: 在frame1中加载frame2中的页面

6: parent.frame2.document.location = “135b.html”;

68 在框架页面之间共享脚本

如果在frame1中html文件中有个脚本

1: function doAlert() {

2: window.alert(“Frame 1 is loaded”);

3: }

那么在frame2中可以如此调用该方法

1: <body onLoad=”parent.frame1.doAlert();”>

2: This is frame 2.

3: </body>

69 数据公用

可以在框架页面定义数据项,使得该数据可以被多个框架中的页面公用

1: <script language=”JavaScript”>

2: var persistentVariable = “This is a persistent value”;

3: </script>

4: <frameset cols=”50%,*”>

5: <frame name=”frame1” src="/”138a.html"”>

6: <frame name=”frame2” src="/”138b.html"”>

7: </frameset>

这样在frame1和frame2中都可以使用变量persistentVariable

70 框架代码库

根据以上的一些思路,我们可以使用一个隐藏的框架页面来作为整个框架集的代码库

1: <frameset cols=”0,50%,*”>

2: <frame name=”codeFrame” src="/”140code.html"”>

3: <frame name=”frame1” src="/”140a.html"”>

4: <frame name=”frame2” src="/”140b.html"”>

5: </frameset>

这篇关于对JavaScript一无所知~离精通只差一步之遥的人的文章就介绍到这儿,希望我们推荐的文章对编程师们有所帮助!



http://www.chinasem.cn/article/206487

相关文章

Python将博客内容html导出为Markdown格式

《Python将博客内容html导出为Markdown格式》Python将博客内容html导出为Markdown格式,通过博客url地址抓取文章,分析并提取出文章标题和内容,将内容构建成html,再转... 目录一、为什么要搞?二、准备如何搞?三、说搞咱就搞!抓取文章提取内容构建html转存markdown

在React中引入Tailwind CSS的完整指南

《在React中引入TailwindCSS的完整指南》在现代前端开发中,使用UI库可以显著提高开发效率,TailwindCSS是一个功能类优先的CSS框架,本文将详细介绍如何在Reac... 目录前言一、Tailwind css 简介二、创建 React 项目使用 Create React App 创建项目

vue使用docxtemplater导出word

《vue使用docxtemplater导出word》docxtemplater是一种邮件合并工具,以编程方式使用并处理条件、循环,并且可以扩展以插入任何内容,下面我们来看看如何使用docxtempl... 目录docxtemplatervue使用docxtemplater导出word安装常用语法 封装导出方

Vue中组件之间传值的六种方式(完整版)

《Vue中组件之间传值的六种方式(完整版)》组件是vue.js最强大的功能之一,而组件实例的作用域是相互独立的,这就意味着不同组件之间的数据无法相互引用,针对不同的使用场景,如何选择行之有效的通信方式... 目录前言方法一、props/$emit1.父组件向子组件传值2.子组件向父组件传值(通过事件形式)方

css中的 vertical-align与line-height作用详解

《css中的vertical-align与line-height作用详解》:本文主要介绍了CSS中的`vertical-align`和`line-height`属性,包括它们的作用、适用元素、属性值、常见使用场景、常见问题及解决方案,详细内容请阅读本文,希望能对你有所帮助... 目录vertical-ali

浅析CSS 中z - index属性的作用及在什么情况下会失效

《浅析CSS中z-index属性的作用及在什么情况下会失效》z-index属性用于控制元素的堆叠顺序,值越大,元素越显示在上层,它需要元素具有定位属性(如relative、absolute、fi... 目录1. z-index 属性的作用2. z-index 失效的情况2.1 元素没有定位属性2.2 元素处

Python实现html转png的完美方案介绍

《Python实现html转png的完美方案介绍》这篇文章主要为大家详细介绍了如何使用Python实现html转png功能,文中的示例代码讲解详细,感兴趣的小伙伴可以跟随小编一起学习一下... 1.增强稳定性与错误处理建议使用三层异常捕获结构:try: with sync_playwright(

Vue 调用摄像头扫描条码功能实现代码

《Vue调用摄像头扫描条码功能实现代码》本文介绍了如何使用Vue.js和jsQR库来实现调用摄像头并扫描条码的功能,通过安装依赖、获取摄像头视频流、解析条码等步骤,实现了从开始扫描到停止扫描的完整流... 目录实现步骤:代码实现1. 安装依赖2. vue 页面代码功能说明注意事项以下是一个基于 Vue.js

CSS @media print 使用详解

《CSS@mediaprint使用详解》:本文主要介绍了CSS中的打印媒体查询@mediaprint包括基本语法、常见使用场景和代码示例,如隐藏非必要元素、调整字体和颜色、处理链接的URL显示、分页控制、调整边距和背景等,还提供了测试方法和关键注意事项,并分享了进阶技巧,详细内容请阅读本文,希望能对你有所帮助...

Nginx实现前端灰度发布

《Nginx实现前端灰度发布》灰度发布是一种重要的策略,它允许我们在不影响所有用户的情况下,逐步推出新功能或更新,通过灰度发布,我们可以测试新版本的稳定性和性能,下面就来介绍一下前端灰度发布的使用,感... 目录前言一、基于权重的流量分配二、基于 Cookie 的分流三、基于请求头的分流四、基于请求参数的分