你的正则表达式很好，只要加上周围环境和gflag. /（？〈=src=”）（.*？）（？=”）/g现在你给出了正确的正则表达式。

console.log(`I'm trying to extract the first jpg from a page of text. multiple paragraphs and multiple urls in each, but i only want the first url/jpg, stop after first is matched/returned.

sample page;

this is some text and a url src="https://www.so23123123123l.jpg" more text, more text, more text. more text, more text

more text, more text. this is some text and a url src="https://www.anotherurl.jpg" more text, more text, more text. more text, more text.`.match(/(?<=src=")(.*?)(?=")/ig));

您可以阅读here关于regexp标志的内容。