How to minimize nested if statements? (Ruby) -

I think I often talk about this type of ruby ​​code:

  If the person is the person then Shirt if person.shirt.sleeve ... and end   
 .. which I do to avoid  NoMethodErrors  I am thinking that if by any means I can make it fall in a row, without clearly clear  
  if person & amp; person. Shirt & amp; amp; Actually, I want to make my code more compact.   
 
 
 Inside those IFS, you want to do something with the sleeves, Isn't it?  
 Rail is a good helper, it all goes well, and  zero  gives value otherwise, in this example, if  person.shirt  Or even if the  person  is zero, the effort will also return as zero.  
  If sleeve   
 You can use gem for vanilla ruby ​​which provides similar functionality.  
  if sleeves = person.and.shirt.andAnd. # End your content