javascript权威指南例子（自己写的）

javascript权威指南例子（自己边看边写的） 前面几章的  下载

<! DOCTYPE HTML PUBLIC  " -//W3C//DTD HTML 4.0 Transitional//EN " >
< HTML >
< HEAD >
< TITLE >  New Document  </ TITLE >
</ HEAD >
< BODY >

<!-- sample  1   -->
< script language = " javascript " >
document.write( " <h1>hello this is Factorials</h1> " )
for  (i = 0 ;i < 10 ;i ++ )
{
    document.write(i+"*"+i+"="+i*i);
    document.write("<br />")
}
</ script >


<!-- sample  1  一般的事件  -->
< input type = " button "  value = " click here (eventhander) "  onclick = " alert('you clicked this button!'); " ></ input >


<!-- sample  2   函数调用 无返回值 -->
< br  />   < h3 > sample  2   函数调用 无返回值 </ h3 >< br  />
< script language = " javascript " >
function function1()
{

alert("good");alert("yes");  //语句在不同的行中可以不写分号，建议只要是语句都要写分号。
alert("1")
alert("2")
/**//*
注释

*/
}
</ script >
< br  />
< input type = " button "  value = " function1 "  onclick = " function1(); " ></ input >

<!-- sample  3   求平方根 -->
< br  />   < h3 > sample  3   求平方根 </ h3 >< br  />

< script language = " javascript " >
function countsqrt()
{
    result=Math.sqrt(document.getElementById("numsqrt").value);    //Math.sqrt 计算平方根
    document.getElementById("numsqrt").value=result;    //把计算结果赋值给文本框
    alert(result);
    //alert((255).toString(0x10))  
}

</ script >
< input type = " text "  id = " numsqrt "  value = " 2 "   ></ input >
< input type = " button "  id = " countsqrt "  value = " 计算平方根 "  onclick = " countsqrt(); "   ></ input >

<!-- sample  4   特殊数值的常量 -->
< script language = " javascript " >
    document.write( " <br /> <h3>sample 4 特殊数值的常量</h3><br /> " )
    document.write( " Number.MAX_VALUE:  " + Number.MAX_VALUE + " <br /> " );
    document.write( " Number.MIN_VALUE:  " + Number.MIN_VALUE + " <br /> " );
    document.write( " Number.MIN_VALUE:  " + Number.MIN_VALUE + " <br /> " );
    document.write( " Number.NaN  " + Number.NaN + " <br /> " );
    document.write( " Number.POSTIVE_INFINITY  " + Number.POSTIVE_INFINTITY + " \n\r\f1111<br /> " );
</ script >

<!-- sample  5  字符串常用操作 -->
< script language = " javascript " >
    document.write( " <br /> <h3>sample 5 字符串常用操作</h3><br /> " )
    msg = " wuyisky " ;
    document.write(msg.length);

    function StringOperate()
     {
        var index = document.getElementById("Operate").value;
        var word = document.getElementById("stringInput").value;
        switch (index)
        {
            case "getLength" :
                alert("\""+word+"\" 的长度是：  "+word.length);
                break;
            case "getLastChar" :
                alert("\""+word+"\" 的最后一个字符是：  "+word.charAt(word.length-1));  //charAt:返回指定索引位置处的字符。strObj.charAt(index); strObj 是string类型,index: from 0 to strObj.length-1
                alert("substring(2)结果是： "+word.substring(2) +"  // 从参数的索引位置开始到结尾的子字符串");
                alert("word.substring(2,4)结果是： "+word.substring(2,4) +"  // 从参数1的索引位置开始到参数2的索引位置结束");
                alert("word.substr(2,4)结果是： "+word.substr(2,4) +"  // 从参数1的索引位置开始的参数2个字符");
                alert("word.slice(2,4)结果是： "+word.slice(2,4) +"  // 从参数1的索引位置开始的参数2个字符");
                break;
            default :
                alert(word);
        }
            
    }
</ script >
< input type = " text "  id = " stringInput "   value = " 被操作的字符串 " ></ input >
< select id = " Operate "  onchange = " StringOperate(); " >
     < option value = " getLength " > 求长度 </ option >
     < option value = " getLastChar " > 取最后一个字符 </ option >
     < option value = " 2 " > 求长度 </ option >
     < option value = " 3 " > 求长度 </ option >

</ select >
     <!-- sample  6   函数直接量 -->
< script language = " javascript " >
    document.write( " <br /> <h3>sample 6 函数直接量</h3><br /> " )
    var f = function(x)  {return x} ;
    var s = f( " 函数直接量； " )
    document.write(s);
    
</ script >

     <!-- sample  7   对象直接量 -->
< script language = " javascript " >
    document.write( " <br /> <h3>sample 7 对象直接量</h3><br /> " )
    var point  =   new  Object();     // create a Object
    point.x = 2 ;         // 属性x
    point.y = 3 ;         // 属性y
    document.write(point.x.toString() + point.y.toString());
    var point1 = {x:2,y:3} ;     // 对象直接量
    document.write(point1.x.toString() + point1.y.toString());
</ script >



     <!-- sample  8  数组的使用 -->
< script language = " javascript " >
    document.write( " <br /> <h3>sample 8 数组的使用</h3><br /> " )
    var a  =   new  Array();
    a[ 0 ]  =   1 ;
    a[ 1 ]  =   " wuyi " ;
    a[ 2 ]  =   true ;
    a[ 3 ]  =   {x:1,y:"a string"} ;
     for  (i  = 0 ;i <= 3 ;i ++ )
     {
        document.write("<br />"+a[i]);
    }
    document.write(a[ 3 ].x + a[ 3 ].y);
</ script >

<!-- sample  9  数组的使用 -->
< br  />   < h3 > sample  9  函数中声明的所有变量在整个函数中都有定义 </ h3 >< br  />


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