<!DOCTYPE html> <html> <head> <base id="myBaseId" href="http://www.sou-xun.com/jsref/" /> </head> <body> <p>单击按钮以显示 base 元素的 href 属性的值。</p> <button onclick="myFunction()">试一试</button> <p id="demo"></p> <script> function myFunction() { var x = document.getElementById("myBaseId").href; document.getElementById("demo").innerHTML = x; } </script> </body> </html>