初级.Net面试题

一、请用Javascript写一个方法，替换字符串中指定位置的字符。
///source原始字符串
///index被替换字符串的位置
///newchar要替换字符
function replaceEx(source,index,newchar)
{

}

代码如下：

function replaceEx(source, index, newchar) {
        if (index < 0 || index >= source.length || source.length == 0) {
            return "无效的参数";
        }
        var indexbegin = 0, indexend = source.length;
        var sFrontPart = source.substr(indexbegin, index);
        var sTailPart = source.substr(index + 1, source.length);
        var result = sFrontPart + newchar + sTailPart;
        return result;
    }
    alert(replaceEx('abcdefg',1,'p'));

(注意：substr()为截取字符串方法)
二、数据库中两张表，表结构如下
数据库：sqlserver 2008 r2
表A:id(int)，name(nvarchar(20))，age(int)，mobile(nvarchar(20))，createtime(datetime)
表B:name(nvarchar(20))，mobile(navarchar(20))，age(int)
问题：请写一条sql，筛选表A中age值在18~25之间的数据，放到B中并试以createtime排序
select * from (select A.createtime,B.* from A,B where A.age=B.age) as t where t.age between 18 and 25 order by t.createtime asc;

select a.createtime,b.* from A as a inner join B as b on(a.name=b.name) where b.age between 18 and 25 order by a.createtime desc

select a.createtime,b.* from A as a left outer join B as b on a.age=b.age where b.age between 18 and 25 order by a.createtime desc

select b.*,a.createtime from B as b right outer join A as a on b.age=a.age where b.age between 18 and 25 order by a.createtime desc

三、请看以下C#代码，并写出输出结果并说明原因
static void Main(string[] args)
{
Task.Factory.StartNew(()=>{
Thread.Sleep(2000);
Console.WriteLine(“function1”);
});
var f2=Task.Factory.StartNew(()=>{
return “function2”;
});
Console.WriteLine(f2.Result);
var r3=“r3”;
var f3=Task.Factory.StartNew(()=>{
r3=“function3”;
});
Console.WriteLine(r3);
Console.Readkey();
}