<textarea id="txt">
lkasdjflwqerqrjdfl;sa <start> asfdlk;jasdklfjas <end> adfasdflkj;kljasdf   
asdfiojas;dfkjas;lkdf <start> alkjfasl;kjdfas <end> fsdafsadf   asfdasdf   asdfasdfasd <start> 1235456 <end> asdfasdfasdfsad
</textarea><script>
var txt=document.getElementById("txt").value;
var reg=/<start>(?:(?!<end>).)*<end>/g;
var arr=txt.match(reg);//得到的是数组
alert(arr.join(""));
</script>

解决方案 »

  1.   

    有一句换一下 .换成[\s\S]var reg=/<start>(?:(?!<end>)[\s\S])*<end>/g;
      

  2.   

    所以把.换成[\s\S]咯~~[\s\S]就是通杀的意思~~
    如果标签也有换行的话!~得改改~不过一般标签是不允许换行的~~
    <textarea id="txt">
    lkasdjflwqerqrjdfl;sa <start> asfdlk;jasdklfjas <end> adfasdflkj;kljasdf   
    asdfiojas;dfkjas;lkdf <start> alkjfasl;kjdfas <end> fsdafsadf   asfdasdf   asdfasdfasd <start> 1235456 <end> asdfasdfasdfsad
    </textarea><script>
    var txt=document.getElementById("txt").value;
    var reg=/<\n?s\n?t\n?a\n?r\n?t\n?>(?:(?!<\n?e\n?n\n?d\n?>)[\s\S])*<\n?e\n?n\n?d\n?>/ig;//标签可换行,而且不区分大小写
    var arr=txt.match(reg);
    alert(arr.join(""));
    </script>
      

  3.   

    忘了用ubb<textarea   id="txt"> 
    lkasdjflwqerqrjdfl;sa   <start>   asfdlk;jasdklfjas   <end>   adfasdflkj;kljasdf       
    asdfiojas;dfkjas;lkdf   <start>   alkjfasl;kjdfas   <end>   fsdafsadf       asfdasdf       asdfasdfasd   <start>   1235456   <end>   asdfasdfasdfsad 
    </textarea> <script> 
    var   txt=document.getElementById("txt").value; 
    var   reg=/ <\n?s\n?t\n?a\n?r\n?t\n?> (?:(?! <\n?e\n?n\n?d\n?> )[\s\S])* <\n?e\n?n\n?d\n?> /ig;//标签可换行,而且不区分大小写 
    var   arr=txt.match(reg); 
    alert(arr.join("")); 
    </script> 
      

  4.   

    妈的,给加上那么多空格了~~<textarea id="txt">
    lkasdjflwqerqrjdfl;sa <start> asfdlk;jasdklfjas <end> adfasdflkj;kljasdf   
    asdfiojas;dfkjas;lkdf <start> alkjfasl;kjdfas <end> fsdafsadf   asfdasdf   asdfasdfasd <start> 1235456 <end> asdfasdfasdfsad
    </textarea><script>
    var txt=document.getElementById("txt").value;
    var reg=/<\n?s\n?t\n?a\n?r\n?t\n?>(?:(?!<\n?e\n?n\n?d\n?>)[\s\S])*<\n?e\n?n\n?d\n?>/ig;//标签可换行,而且不区分大小写
    var arr=txt.match(reg);
    alert(arr.join(""));
    </script>