问题
There are some discussions here, and utility functions, for splitting strings, but I need an ad-hoc one-liner for a very simple task.
I have the following string:
local s = "one;two;;four"
And I want to split it on ";"
. I want, eventually, go get { "one", "two", "", "four" }
in return.
So I tried to do:
local s = "one;two;;four"
local words = {}
for w in s:gmatch("([^;]*)") do table.insert(words, w) end
But the result (the words
table) is { "one", "", "two", "", "", "four", "" }
. That's certainly not what I want.
Now, as I remarked, there are some discussions here on splitting strings, but they have "lengthy" functions in them and I need something succinct. I need this code for a program where I show the merit of Lua, and if I add a lengthy function to do something so trivial it would go against me.
回答1:
local s = "one;two;;four"
local words = {}
for w in (s .. ";"):gmatch("([^;]*);") do
table.insert(words, w)
end
By adding one extra ;
at the end of the string, the string now becomes "one;two;;four;"
, everything you want to capture can use the pattern "([^;]*);"
to match: anything not ;
followed by a ;
(greedy).
Test:
for n, w in ipairs(words) do
print(n .. ": " .. w)
end
Output:
1: one
2: two
3:
4: four
回答2:
function split(str,sep)
local array = {}
local reg = string.format("([^%s]+)",sep)
for mem in string.gmatch(str,reg) do
table.insert(array, mem)
end
return array
end
local s = "one;two;;four"
local array = split(s,";")
for n, w in ipairs(array) do
print(n .. ": " .. w)
end
result:
1:one
2:two
3:four
来源:https://stackoverflow.com/questions/19907916/split-a-string-using-string-gmatch-in-lua