问一个碰到的问题

hmchzb19

http://www.codecademy.com/course ... 8619189a5000201fbcb


这个页面
我的code 如下：

1. def alphabetize(arr,rev=false)
   
2.     arr.sort!
   
3.     if rev
   
4.         return arr
   
5.     else
   
6.         return arr.reverse!
   
7.     end
   
8. end
   
9. 
   
10. 
    
11. numbers=[13,2,4,563,21,123]
    
12. 
    
13. puts alphabetize(numbers)

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这是页面的错误提示，我怎么看不出来我哪里出错了？

Oops, try again. It looks like your method doesn't default to alphabetizing an array when it doesn't receive a second parameter.

rubyish

After your .sort! call, add an if statement.

If rev is true, call reverse! on arr.

1. def alphabetize(ary, rev = false)
   
2.   ary.sort!
   
3.   if rev
   
4.     return ary.reverse!
   
5.   else
   
6.     return ary
   
7.   end
   
8. end
   
9. 
   
10. numbers = [13, 2, 4, 563, 21, 123]
    
11. 
    
12. p alphabetize numbers

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hmchzb19

If rev is true, call reverse! on arr.

但是rev 默认是false

所以默认是直接进入else的啊

rubyish

ru ?

1. p alphabetize numbers, true

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Start Here
follow the instructions

1. Start Here
   
2. 
   
3. Each lesson starts here. Read the explanation, then follow the instructions underneath. If you get stuck, you can click on the "Hint" for help.

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Instructions

1. After your .sort! call, add an if statement. If rev is true, call reverse! on arr.

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If rev is true, call reverse! on arr.

1.   if rev      #  If rev is true,
   
2.     return ary.reverse!      #  call reverse! on arr.
   
3.   else

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