查找字符串中字符的最后一个索引 [英] Find the last index of a character in a string

问题描述

我希望能够对Lua(Luvit)项目中的字符串使用lastIndexOf方法.不幸的是，没有内置这种方法，我现在有点卡住了.

I want to have ability to use a lastIndexOf method for the strings in my Lua (Luvit) project. Unfortunately there's no such method built-in and I'm bit stuck now.

在Javascript中，它看起来像:

In Javascript it looks like:

'my.string.here.'.lastIndexOf('.')     // returns 14

推荐答案

function findLast(haystack, needle)
    local i=haystack:match(".*"..needle.."()")
    if i==nil then return nil else return i-1 end
end
s='my.string.here.'
print(findLast(s,"%."))
print(findLast(s,"e"))

请注意，要找到.，您需要对其进行转义.

Note that to find . you need to escape it.

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