javascript Get the regular expression within the first slash in the linked file address_javascript skills

window.location.pathname
比如：
/windows/location/page.html
我想得到“windows”，请问用正则表达式怎么写？

<script> var a="/windows/location/page.html"; var reg=/(^(http[s]?:\/\/[^\/]*\/)|(^\/))([^\/]+)\/.*$/ig; var t=a.replace(reg,"$4"); alert(a + "\n" + "\n" + t); var a=top.location + "/windows/location/page.html"; var t=a.replace(reg,"$4"); alert(a + "\n" + "\n" + t); alert(top.location + "\n" + "\n" + reg.test(top.location)); </script>
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