在 Lua 示例中查找两个字符串文本的"差异"

local function get_inserted_text(old, new)
   local prv = {}
   for o = 0, #old do
      prv[o] = ""
   end
   for n = 1, #new do
      local nxt = {[0] = new:sub(1, n)}
      local nn = new:sub(n, n)
      for o = 1, #old do
         local result
         if nn == old:sub(o, o) then
            result = prv[o-1]
         else
            result = prv[o]..nn
            if #nxt[o-1] <= #result then
               result = nxt[o-1]
            end
         end
         nxt[o] = result
      end
      prv = nxt
   end
   return prv[#old]
end

用法：

print(get_inserted_text("hello there", "hello.there"))    -->  .
print(get_inserted_text("hello there", "hello()there"))   -->  ()
print(get_inserted_text("hello there", "hello htere"))    -->  h
print(get_inserted_text("hello there", "heLlloU theAre")) -->  LUA

只需迭代字符串并找出它们不匹配的位置。

function StringDifference(str1,str2)
    for i = 1,#str1 do --循环字符串
        if str1:sub(i,i) ~= str2:sub(i,i) then --如果该字符不等于它的对应字符
            return i --返回该索引
        end
    end
    return #str1+1 --返回较短的字符串结束后的索引作为备用。
end

print(StringDifference("hello there", "hello.there"))