local function main()
local grid = initGrid(4,4)
randomNum(grid)
printGrid(grid)
io.write("next step 'a'[←],'w'[↑],'s'[↓],'d'[→],'q'[exit] >> ")
local input = io.read()
while input~="q" do
if input=="a" or input=="w" or input=="s" or input=="d" then
if input=="a" then
moveLeft(grid)
elseif input=="w" then
moveUp(grid)
elseif input=="s" then
moveDown(grid)
elseif input=="d" then
moveRight(grid)
end
randomNum(grid)
printGrid(grid)
else
print("error input. please input 'a'[←] or 'w'[↑] or 's'[↓] or 'd'[→] or 'q'[exit]")
end
io.write("next step 'a'[←],'w'[↑],'s'[↓],'d'[→],'q'[exit] >> ")
input = io.read()
end
end

找不到但直到是end

对齐之后一目了然