RegEx非捕获组问题

Question

为什么关注返回["vddv"]而不是[“dd”]：

"aaavddv".match(/(?:v).*(?:v)/)

Answer 1

(?:v) # matches 'v' this is a non-capturing group, not a lookbehind
.*    # matches 'dd'
(?:v) # matches 'v' this is a non-capturing group, not a lookahead

非捕获组仍然参与比赛。也许你想要前瞻/落后？但是Javascript不支持lookbehind。

Answer 2

"aaavddv".match(/(?:v)(.*)(?:v)/)[1]

整个匹配正确vddv但如果您只想匹配dd，则需要使用捕获组（并查看元素[1]）

Answer 3

/(?:v).*(?:v)/指定表达式v（字符数）v