ruby中的流程控制

1、 if语句

else if 简写成elsif

if sum > 1000
   puts "big"
elsif sum >500
   puts "medium"
else
   puts "small"
end

2、三元运算

x = 5
puts x > 3 ? "bigger":"smaller"

3、case语句

name = "kaka"
case name
   while "tony" 
       puts "hello tony"
   while "mike"
       puts "hello mike"
   else 
       puts "hi#{name}"
end

4、while、loop、until，next and break

x = 0
while x < 10
   x += 1
   next if x%2 == 0
   print x,"\n"
end

x = 0
loop do 
   x += 1
   break if x >10
end

x = 0
x += 1 until x > 10
puts x # x => 11

在ruby中，只有false或者nil为假，其它都为真