1 
< script language = ”JavaScript” >
2 JavaScript code goes here
3 </ script >
< script language = ”JavaScript” > 2
JavaScript code goes here3
</ 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 < script language = ”JavaScript” > 2
<!-- 3
document.write(“Hello”);4
// --> 5
</ script > 3 浏览器不支持的时候显示
1 < noscript >
2 Hello to the non - JavaScript browser.
3 </ noscript >
< 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 >
< script language = ”JavaScript” src = " /”filename.js " ” ></ script > 5 注释脚本
1
2 // This is a comment
3 document.write(“Hello”); // This is a comment
4
2
// This is a comment 3
document.write(“Hello”); // This is a comment 4
6 输出到浏览器
1 document.write(“ < strong > Hello </ strong > ”);
document.write(“ < strong > Hello </ strong > ”); 7 定义变量
1 var myVariable = “some value”;
var myVariable = “some value”; 8 字符串相加
1 var myString = “String1” + “String2”;
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 >
< 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
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 >
< 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 );
4myArray[ 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 >
< 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 >
< 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 >
< 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 >
< 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 >
< 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 >
< 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 >
< 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 >
< body onLoad = ”functionName();” > 2
Body of the page3
</ 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 >
< 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 >
12
< 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 > 12
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 >
9
< script > 2
<!-- 3
function hello() { 4
window.alert(“Hello”);5
} 6
window.setTimeout(“hello()”, 5000 );7
// --> 8
</ script > 9
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 >
< 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 >
< 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 >
4
< body onUnload = ”functionName();” > 2
Body of the page3
</ body > 4