js 在线演示

function runCode(obj)
{ 
var winname = window.open('', "_blank", '');
winname.document.open('text/html', 'replace');
winname.opener = null
winname.document.writeln(obj.value);
winname.document.close();
}
function copycode(obj)
{
var rng = document.body.createTextRange();
rng.moveToElementText(obj);
rng.scrollIntoView();
rng.select();
rng.execCommand("Copy");
rng.collapse(false);
alert("代码已经复制到剪切板");
}

转载自：https://blog.csdn.net/sondx/article/details/6687921