while while循环中的循环

Question

"hello"仅由puts打印三次。应该打印六次，不是吗？

i = 0
j = 0
while(i != 2)
    while(j != 3)
            puts "hello"
            j += 1
    end
i += 1
end

Answer 1

您必须在内部j循环之外将0设置为while。

i = 0
j = 0
while(i != 2)
    while(j != 3)
            puts "hello"
            j += 1
    end
# this is needed, as inside the upper loop, you made j to 3 after 3 iteration.
# thus you need to reset it to 0 again, to start again 3 times iteration.
j = 0 
i += 1
end
# >> hello
# >> hello
# >> hello
# >> hello
# >> hello
# >> hello

---

更好的是 -

i = 0
while(i != 2)
  j = 0
  while(j != 3)
    puts "hello"
    j += 1
  end
  i += 1
end

Answer 2

如果你使用循环{}，你可能会更容易 - 即使你必须自己跟踪计数器，我发现它比使用while或xxtimes更容易理解，也可以正常工作。