n.子組

子集.

These subgroups can be recalled for the same match or search, or extracted for post-processing. 這些子組在相同的匹配或搜索中被重復(fù)調(diào)用，或稍后處理中提取。

Why are matches of subgroups important?The main reason is that there are times where you want to extract the patterns you match, in addition to making a match. 使用圓括號(hào)的一個(gè)額外好處就是匹配的子串會(huì)被保存到一個(gè)子組，便于今后使用。