If all possible paths through the regex have been attempted but a match was not found, the regex engine goes back to step 2 to try again at the next character in the string.

如果正则表达式的所有可能路径都尝试过了，但是没有成功地匹配，那么正则表达式引擎回到第二步，从字符串的下一个字符重新尝试。

youdao

If all possible paths through the regex have been attempted but a match was not found, the regex engine goes back to step 2 to try again at the next character in the string.

如果正则表达式的所有可能路径都尝试过了，但是没有成功地匹配，那么正则表达式引擎回到第二步，从字符串的下一个字符重新尝试。

youdao