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JavaScript就这么回事1:基础知识

JavaScript就这么回事1:基础知识
 
有些时候你精通一门语言,但是会发现你其实整天在和其它语言打交道,也许你以为这些微不足道,不至于影响你的开发进度,但恰恰是这些你不重视的东西会浪费你很多时间,我一直以为我早在几年前就已经精通JavaScript了,直到目前,我才越来越觉得JavaScript远比我想象的复杂和强大,我开始崇拜它,就像崇拜所有OOP语言一样~
趁着节日的空隙,把有关JavaScript的方法和技巧整理下,让每个在为JavaScript而烦恼的人明白,JavaScript就这么回事!并希望JavaScript还可以成为你的朋友,让你豁然开朗,在项目中更好的应用~

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

 

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[i] + “<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>

posted on 2006-03-01 15:07  多想,多做,多努力  阅读(94)  评论(0)    收藏  举报