使用正则表达式在字符串第n次出现后捕获

如果可能的话,不要使用正则表达式,我建议你阅读- https://blog.codinghorror.com/regular-expressions-now-you-have-two-problems/ 博客帖子

对于你的问题,使用劈裂更容易、更快、更防弹

const articleName = "/custom-heads/food-drinks/51374-easter-bunny-cake".split("/")[3]
// '51374-easter-bunny-cake'

const articleId = articleName.split("-")[0]

// '51374'

希望有帮助

您可以将此正则表达式与捕获组一起使用:

^(?:[^\/]*\/){3}([^-]+)

或者在现代浏览器中,可以使用lookback断言:

/(?<=^(?:[^\/]*\/){3})[^-]+/

RegEx Demo 1

RegEx Demo 2

正则表达式代码:

• ^ :开始
• (?:[^\/]*\/){3} :匹配0个或多个非- / 字符后跟 / .重复这组动作3次
• ([^-]+) :匹配1+个非连字符

代码:

const s = `/custom-heads/food-drinks/51374-easter-bunny-cake`;

const re = /^(?:[^\/]*\/){3}([^-]+)/;

console.log (s.match(re)[1]);

使用

const str = `/custom-heads/food-drinks/51374-easter-bunny-cake`
const p = /(?:\/[^\/]*){2}\/(\d+)-/
console.log(str.match(p)?.[1])

看见 regex proof .

解释

Non-capturing group (?:\/[^\/]*){2}
{2} matches the previous token exactly 2 times
\/ matches the character / with index 4710 (2F16 or 578) literally (case sensitive)
  Match a single character not present in the list below [^\/]
  * matches the previous token between zero and unlimited times, as many times as possible, giving back as needed (greedy)
  \/ matches the character / with index 4710 (2F16 or 578) literally (case sensitive)
\/ matches the character / with index 4710 (2F16 or 578) literally (case sensitive)
1st Capturing Group (\d+)
  \d matches a digit (equivalent to [0-9])
  + matches the previous token between one and unlimited times, as many times as possible, giving back as needed (greedy)
- matches the character - with index 4510 (2D16 or 558) literally (case sensitive)