CODEWITHSUNDEEP
lua
hc ch
hc ch

Reputation: 137

lua string.match does't match as expected(different with other language)

a = "stackoverflow.com/questions/ask"
print(string.match(a,"(.*/)"))   -- stackoverflow.com/questions/
print(string.match(a,"(.*/).*")) -- stackoverflow.com/questions/

I can't understand the second result. In my option it should be "stackoverflow.com/questions/ask" as "(.*/)" matches "stackoverflow.com/questions/" and ".*" matches "ask". Can someone tell me WHY the second result is "stackoverflow.com/questions/" ? Does x = string.match(a,"(.*/).*") and x = string.match(a,"(.*/)") are same?

Upvotes: 2

Views: 151

Answers (1)

上山老人
上山老人

Reputation: 462

the () means you have used Captures.so maybe you can use it like this:

print(string.match(a,"((.*/).*)"))

Captures:

A pattern can contain sub-patterns enclosed in parentheses; they describe captures. When a match succeeds, the substrings of the subject string that match captures are stored (captured) for future use. Captures are numbered according to their left parentheses. For instance, in the pattern "(a*(.)%w(%s*))", the part of the string matching "a*(.)%w(%s*)" is stored as the first capture (and therefore has number 1); the character matching "." is captured with number 2, and the part matching "%s*" has number 3.

Upvotes: 1

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