javascript - 如何使用正则表达式获取最后一个模式

Question

var a = 'a.b.c.d.e.f'
a = a.split('.');
var len = a.length;
var pattern = a[len-2]+'.'+a[len-1]
console.log(pattern);

它工作得非常好，但我必须使用正则表达式来做，有没有办法我们可以使用正则表达式获得相同的结果

或任何其他方式，这将是仅获取最后 2 个用点 (.) 字符分隔的字符串的有效解决方案。

Answer 1

您可以使用正则表达式来查找由点分隔的最后一个字符。

/[^.]+\.[^.]+$/

• [^.]+ match a single character not present in the list below

  Quantifier: + Between one and unlimited times, as many times as possible, giving back as needed [greedy]

  . the literal character .

• \. matches the character . literally

• [^.]+ match a single character not present in the list below

  Quantifier: + Between one and unlimited times, as many times as possible, giving back as needed [greedy]

  . the literal character .

• $ assert position at end of the string

console.log('a.b.c.d.e.f'.match(/[^.]+\.[^.]+$/, ''));
console.log('zz.yy.xx.ww.vv.uu'.match(/[^.]+\.[^.]+$/, ''));
console.log('number with.dot'.match(/[^.]+\.[^.]+$/, ''));