特殊的转义字符 "\v"

/*
官网原文：
    JScript does not support the \v vertical tab character as a      white   space character. It treats \v as v. 
Example: 
*/
<script> alert('\v supported ' + (String.fromCharCode(11) == '\v')); </script> 
/*
     Output: IE: false 
             FF: true 
             Opera: true 
             Safari: true
*/