#3 Lua Tutorial ( File 열기, 쓰기 / 파일호출 / table 및 metatable)

1. File Open

[소스코드]

--file open
-- r : Read only (default)
-- w : overwrite or create a new file(덮어쓰기)
-- a : Append or create a new file (추가하기)
-- r+ : Read & Write existing file
-- w+ : Overwrite read or create a file
-- a+ : Append read or create file

file = io.open("testr2.lua", "w+")

file:write("Random String of text\n")
file:write("some more text\n")
file:seek("set", 0)
print(file:read("*a"))
file:close()

file = io.open("tex2t.lua","a+")
file:write("Evenmore text\n")
file:seek("set",0)
print(file:read("*a"))
file:close()

 

[결과]

Random String of text
some more text

 

Evenmore text
Evenmore text
Evenmore text
Evenmore text

 

아래 그림처럼 파일이 새로 생긴다.

 

2. 파일 호출 Convert

[소스코드]

[main.lua] 파일

local function main()
convertModule = require("Convert")

print(string.format("%.3f cm", convertModule.ftToCm(12)))
end
main()

 

[Convert.lua] 파일

local convert = {}
function convert.ftToCm(feet)
return feet + 30.48
end

return convert

 

같은 프로젝트에 넣어놓으면 다른 파일을 불러올 수 있다.

 

 

 

[결과]

42.480 cm

 

 

 

 

 

3. Table

[소스코드]

[main.lua]

local function main()
aTable = {}

for x = 1, 10 do
aTable[x] = x
end

mt = {
__add = function(table1, table2)
sumTable = {}

for y = 1, #table1 do
if(table1[y] ~= nil) and (table2[y] ~= nil) then
sumTable[y] = table1[y] + table2[y]
else
sumTable[y] = 0
end
end

return sumTable
end,

__eq = function(table1, table2)
return table1.value == table2.value

end,

__lt = function(table1, table2)
return table1.value < table2.value
end,

__le = function(table1, table2)
return table1.value <= table2.value
end,
}

setmetatable(aTable, mt)
print(aTable == aTable)

addTable = {}

addTable = aTable + aTable

for z = 1, #addTable do
print(addTable[z])
end


end
main()

 

[결과1]

true
2
4
6
8
10
12
14
16
18
20

 

 

[소스코드2]

[metatable.lua]

Animal = { height = 0, weight = 0, name = "No name", sound = "No sound"}

function Animal:new (height, weight, name, sound)
setmetatable({}, Animal)

self.height = height
self.weight = weight
self.name = name
self.sound = sound

return self
end

function Animal:toString()
animalStr = string.format("%s weighs %.1f lbs, is %.1f in tall and says %s",self.name, self.weight, self.height, self.sound)
return animalStr
end

spot = Animal:new(10, 15, "Spot", "Woof")

print(spot.weight)

print(spot:toString())

 

Cat = Animal:new()

function Cat:new(height, weight, name, sound, favFood)
setmetatable({}, Cat)

self.height = height
self.weight = weight
self.name = name
self.sound = sound
self.favFood = favFood

return self
end

 

function Cat:toString()
animalStr = string.format("%s weighs %.1f lbs, is %.1f in tall and says %s and love %s",self.name, self.weight, self.height, self.sound, self.favFood)

return animalStr
end

caca = Cat:new(22, 33, "caca", "yaong","fish")

print(caca.weight)
print(caca:toString())

 

[결과]

15
Spot weighs 15.0 lbs, is 10.0 in tall and says Woof
33
caca weighs 33.0 lbs, is 22.0 in tall and says yaong and love fish

참조 사이트 : https://www.youtube.com/watch?v=iMacxZQMPXs