how to split file extention using regex

Question

how to split with regex from asddhj123.png.png to 123.png

I have tried with regex below, but the first extension still involved :(

 /[a-zA-z.]|\.(jpg|png)$/

i hope that will be return :

asdasd123.jpg.jpg => 123.jpg

dsds345.png.png => 345.png

Answer 1

This expression is likely to return the desired outputs:

(?i)\d+\.(?:jpe?g|png)

---

If you wish to explore/simplify/modify the expression, it's been explained on the top right panel of regex101.com. If you'd like, you can also watch in this link, how it would match against some sample inputs.

---

const regex = /\d+\.(?:jpe?g|png)/gmi;
const str = `asdasd123.jpg.jpg => 123.jpg
asdasd123.jpeg.jpeg => 123.jpeg
dsds345.png.png => 345.png

`;
let m;

while ((m = regex.exec(str)) !== null) {
	if (m.index === regex.lastIndex) {
		regex.lastIndex++;
	}

	m.forEach((match, groupIndex) => {
		console.log(match);
	});
}