for循环遍历

1.数值for

for i = 1,10,1 do --初值,终值，步数（正数则每次循环加该数，负数则i减该数），步数可以省略（默认为1）
 	print(i*2); --2,4,6,...20
 end

2.泛型for in pairs

这种遍历表的方式会遍历所有的键值对

days = {"Sunday", x = 1, y = 2,"Monday", "Tuesday", "Wednesday", 
 "Thursday", "Friday", [20] = "aaa","Saturday"}

 for k,v in pairs(days) do
 	print(k,v)//{1,Sunday},{2,Monday},{3,Tuesday},...,{7,Saturday},{x,1},{20,"aaa"}{y,2}
 end

2.泛型for in ipair

这种遍历表的方式会从数字索引(interger key)1开始遍历，如果下一个数字索引不存在，则结束

days = {"Sunday", x = 1, y = 2,"Monday", "Tuesday", "Wednesday", 
 "Thursday", "Friday",[20] = "aaa", "Saturday"}

 for k,v in ipairs(days) do
 	print(k,v)//{1,Sunday},{2,Monday},{3,Tuesday},...,{7,Saturday}
 end