-- 1. if end a=1 if a==1 then print(a) end -- 2. if else end b=1 if b < 10 then print('b<10 and b='..b) else print('b>10 and b='..b) end -- 3. if elseif else end score=64 if score>=0 and score<60 then print('不及格, score='..score) elseif score>=60 and score<80 then print('成績中等, score='..score) elseif score>=80 and score<=100 then print('成績優良, score='..score) else print('錯誤的分數!, score='..score) end