javascript字符串长度截取函数详解编程语言

function cutstr(str, len) { 
    var temp, 
        icount = 0, 
        patrn = /[^/x00-/xff]/， 
        strre = ""; 
    for (var i = 0; i < str.length; i++) { 
        if (icount < len - 1) { 
            temp = str.substr(i, 1); 
                if (patrn.exec(temp) == null) { 
                   icount = icount + 1 
            } else { 
                icount = icount + 2 
            } 
            strre += temp 
            } else { 
            break; 
        } 
    } 
    return strre + "..." 
}