lua 学习

nil、boolean、number、string、function、table、userdata、thread

local a = "hello wordld"
local b = 1

if XXXXX then

end


如果 nil 进行比较 需使用 "nil"
if a == "nil" then
end

if XXXXX then

elseif then

end

// 输出a变量的值
print(a) 
// 输出a变量的类型
print(type(a))

	local table1 = {"zhangsan","lisi","wangwu"}

	-- Lua 里表的默认初始索引一般以 1 开始
	for k, v in pairs(table1) do
		print("Key:", v)
		if k == 2 then
			break
		end
	end


结果输出：
Key:	zhangsan
Key:	lisi

function APlusB(a,b)
   return a + b;
end

local c = APlusB(1,2);
 print(c)

function(...)
    for k,v in pairs(...) do
        print(v)
    end
end

//格式化字符串
string.format("the value is:%d",4)

//转化为 string
string.format()

array = {"Lua", "Tutorial"}

for i= 0, 2 do
   print(array[i])
end

tonumnber("1")
tostring(1)

	-- 定义一个表 tb 里面有4个元素
 	local tb = {
		[1] = "A";
		[2] = "B";
		[3] = "C";
		[4] = "D";
	}
	
	print("mytable 索引为 1 的元素是 ", tb[1])
	print("---------")
	for k,v in ipairs(tb) do
            print(k,v)
	end

	print("---------")

	-- 删除tb表 索引为1的值
	table.remove(tb ,1)
	for k,v in ipairs(tb) do
            print(k,v)
	end

	print("---------")

	-- 插入到tb表 索引为1 值为"A"
	table.insert(tb ,1 ,"A")
	for k,v in ipairs(tb) do
            print(k,v)
	end
	-- 最终表的数据还是最初定义的样子

function ToStringEx(value)
    if type(value)=='table' then
       return TableToStr(value)
    elseif type(value)=='string' then
        return "\'"..value.."\'"
    else
       return tostring(value)
    end
end

function StrToTable(str)
    if str == nil or type(str) ~= "string" then
        return
    end
    
    return loadstring("return " .. str)()
end

function TableToStr(t)
    if t == nil then return "" end
    local retstr= "{"

    local i = 1
    for key,value in pairs(t) do
        local signal = ","
        if i==1 then
          signal = ""
        end

        if key == i then
            retstr = retstr..signal..ToStringEx(value)
        else
            if type(key)=='number' or type(key) == 'string' then
                retstr = retstr..signal..'['..ToStringEx(key).."]="..ToStringEx(value)
            else
                if type(key)=='userdata' then
                    retstr = retstr..signal.."*s"..TableToStr(getmetatable(key)).."*e".."="..ToStringEx(value)
                else
                    retstr = retstr..signal..key.."="..ToStringEx(value)
                end
            end
        end

        i = i+1
    end

     retstr = retstr.."}"
     return retstr
end