zoukankan      html  css  js  c++  java
  • 异常

    <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
    <html xmlns="http://www.w3.org/1999/xhtml" >
    <head>
        <title>5-11</title>
    </head>
    <body>
    <script language="javascript">
    try
    {
        var n = error;          // 人为引发一个错误
    }
    catch( e )            
    {
        alert( (e.number&0xFFFF) + "号错误:" + e.description );// 错误处理:仅输出错误信息
    }
    </script>
    </body>
    </html>

    out

    <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
    <html xmlns="http://www.w3.org/1999/xhtml" >
    <head>
        <title>5-12</title>
    </head>
    <body>
    <script language="javascript">
    try
    {
        var fruit = new Array( "鸭梨", "苹果", "葡萄", "李子" );    // 水果
        for( n=0; n<fruit.length; m++ )                             // 遍历数组,在此人为引发一个异常
        {
            document.write( fruit[n] + " " );
        }
    }
    catch( e )            
    {
        alert( (e.number&0xFFFF) + "号错误:" + e.description );    // 处理异常
    }
    finally                                                         // finally块中清除数组所占的资源
    {
        fruit = null;
        alert( "fruit="+fruit+"已经断开fruit数组的引用!");
    }
    </script>
    </body>
    </html>

    除数为0异常

    <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
    <html xmlns="http://www.w3.org/1999/xhtml" >
    <head>
        <title>5-13</title>
    </head>
    <body>
    <script language="javascript">
    try
    {
        var total = 100;
        var parts = 0;
        if( parts == 0 )                    // 如果除数为0则抛出异常
        {
            throw "Error:parts is zero";
        }
        alert( "每人"+total/parts+"份");    //此处将捕获try块中抛出的异常
    }
    catch( e )
    {
        alert( e );
    }
    </script>
    </body>
    </html>

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  • 原文地址:https://www.cnblogs.com/huodaihao/p/7328015.html
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