条件控制

本人喜欢用程序demo记录的方式来记录某方法的使用，如times方法，仅作个人学习记录

 

#--------------if语句(相反是unless)而while相同于until--------------print "--------------if------------------------ps: in ruby,the symbol ','just works as plusing string\n"x = 0if x==0 then endp "x=0" if x==0unless x!=0 then end#-->here is the way to use until(while)#begin# ...#end until (condition)#--------------case语句------------------------p "--------------case------------------------"scale =8  case scale    when  1..5then p "low"    when 6..10then p "high"  else        p "default"end    p "--------------cycle------------------------" 3.times{|i| print i," "}  print "\n next let`s look at *upto* method\n"0.upto(2){|i| print i," "}print "\n next let`s look at *downto* method\n"2.downto(0){|i| print i," "}