如何从 javascript 中的 URI 中提取文件名？

Question

I have an URL like this -

https://firebasestorage.googleapis.com/v0/b/sathyatest12-blog.appspot.com/o/85fa93fa-1ca7-4055-b6b3-6a41db4s498b-testcup1.png?alt=media&token=4dfd3ca0-a55b-4052-956c-94a2bs13c77e

of which I need to get the file name. In this case,

85fd93fa-1ca7-4055-b6d3-6a41db4s498b-testcup1.png

I tried using regex as suggested in other answers but I am unable to write complicated expressions.

I tried using JavaScripts Good parts by Coderholic but it is not giving me what I want. I found a generic regex from there which I am pasting below

 var parse_url = /^(?:([A-Za-z]+):)?(\/{0,3})([0-9.\-A-Za-z]+)(?::(\d+))?(?:\/([^?#]*))?(?:\?([^#]*))?(?:#(.*))?$/; var url = 'http://www.ora.com:80/goodparts?q#fragment'; var result = parse_url.exec(url); var names = ['url', 'scheme', 'slash', 'host', 'port', 'path', 'query', 'hash']; var blanks = ' '; var i; for (i = 0; i < names.length; i += 1) { document.writeln(names[i] + ':' + blanks.substring(names[i].length), result[i]); }

But this is giving me

/v0/b/sathyatest12-blog.appspot.com/o/85fa93fa-1ca7-4055-b6b3-6a41db4s498b-testcup1.png

Please help.

Answer 1

Why not simply use the URL API ?

 var URL_val = 'https://firebasestorage.googleapis.com/v0/b/sathyatest12-blog.appspot.com/o/85fa93fa-1ca7-4055-b6b3-6a41db4s498b-testcup1.png?alt=media&token=4dfd3ca0-a55b-4052-956c-94a2bs13c77e', URL_Obj = new URL(URL_val); let lastOne = URL_Obj.pathname.split('/').pop() console.log(`lastOne: ${lastOne}`)

Answer 2

I have solved this problem simply like below

var url_string = "https://firebasestorage.googleapis.com/v0/b/sathyatest12-blog.appspot.com/o/85fa93fa-1ca7-4055-b6b3-6a41db4s498b-testcup1.png?alt=media&token=4dfd3ca0-a55b-4052-956c-94a2bs13c77e"; //window.location.href
firstPos = url_string.lastIndexOf('/');
lastPos = url_string.indexOf('?');
var result = url_string.slice(firstPos+1, lastPos);

console.log(result);

I have tested this on jsfiddle.net

Answer 3

You can also achieve the same result first to reverse the string since we cannot find the last index of / using regex. But we can find the first index of ? if we can reverse the string.

 const str = "https://firebasestorage.googleapis.com/v0/b/sathyatest12-blog.appspot.com/o/85fa93fa-1ca7-4055-b6b3-6a41db4s498b-testcup1.png?alt=media&token=4dfd3ca0-a55b-4052-956c-94a2bs13c77e"; const reverse = str.split("").reverse().join(""); const regex = /(?<=\?)(.*?)\//; const match = reverse.match(regex); if (match) { const result = match[1].split("").reverse().join(""); console.log(result); }