lua语言--table的构建

Posted 2020-08-31

　　table是lua语言中最为重要，也是最为强大的武器，最简单的构造函数是{}。--所以说当你看到{}的时候，实际上是调用了一个构造函数。

　　直接初始化数组：

days = {"Monday","Tuesday","Wednesday"}

　　初始化一个表作为record：

days = {m = "Monday",t = "Tuesday",w="Wednesday"}
//注意record其实相当于以m,t,w作为下表，所以默认的下表days[0]返回nil

　　添加域:可以向表中添加任何类型的域，构造函数{}仅影响初始化。

w = {x = 0,y = 0,label="console"}
x = {sin(0),sin(1),sin(2)}
w[1] = "another field"
x.f = w
//域即键值

　　用table构造链表：

list = nil
for line in io.lines() do
    list = {next = list,value = line}
end

l = list 
while 1 do 
    print(l.value)
    l = l.next
end

　　record和list混搭：

polyline = {color = "blue",thickness = 2,npoints = 4,
			{x = 0, y = 0},
			{x = -10, y = 0},
			{x = -10, y = 1},
			{x= 0, y = 1}
		}

print(polyline[1].x)

　　list和record风格是一般初始化的特例：

{x=0,y=0}    <-->  {["x"]=0,["y"]=0}

{"red","green","blue"}   <--> {[1] = "red",[2] = "green",[3] = "blue"}

　　如果想要数组从0开始：(不建议）

days = {[0] = "Sunday","Monday","Tuesday","Wednesday"}

　　构造函数的,是可选的，方便以后扩展/ ，和；可以相互替代。