Help refactoring this code

Question

Update: the much better answer has little to do with refactoring, but has to do with setting a default for empty keys. See the first answer- thanks a lot guys!

Hi folks, how would you refactor this?

    if n=network_stats["b"]
      network_stats["b"] = n +1 
    else
      network_stats["b"]=1
    end

I have a nagging feeling this can be done in 2 lines

Answer 1

Hi ming yeow

network_stats["b"] = (n == network_stats["b"]? (n + 1) : 1)

hope this helps

cheers

sameera

PS : This is a good site for code refactoring

http://refactormycode.com/

Answer 2

network_stats["b"] = (n == network_stats["b"])? n+1 : 1

Answer 3

I'm going to assume there is a slight typo in your code, and you meant to do a comparison instead of an assignment on the first line, like this:

if n == network_stats["b"]
  network_stats["b"] = n + 1 
else
  network_stats["b"] = 1
end

I would refactor this into something like:

n == network_stats["b"] ? (network_stats["b"] = n + 1) : (network_stats["b"] = 1)

While Christians answer is more precise in terms of bytes used, I find it less readable, but that's simply personal opinion.

In case he removes his answer, it was:

network_stats["b"] = (n == network_stats["b"]) ? n + 1 : 1

Answer 4

Hey Ming you should have known about ternary operators

I think this might help you get around

network_stats["b"] = (n == network_stats["b"]) ? n + 1 : 1

Answer 5

# do this when network_stats is defined
network_stats.default= 0

# to increment the network stats
network_stats["b"] += 1

for example

>> (network_stats={}).default= 0
=> 0
>> network_stats["b"] += 1
=> 1
>> network_stats
=> {"b"=>1}

Answer 6

This is a short and readable oneliner:

network_stats["b"] = (network_stats["b"] || 0) + 1

And a longer but maybe more readable and scalable (when more cases would be added in the future) version:

network_stats["b"] = case network_stats["b"]  
                       when nil then 0  
                       else network_stats["b"] + 1  
                     end  

Update: As a curiosity, this can work to:

 network_stats["b"] += 1 rescue network_stats["b"] = 1

I would not use it personally.

Answer 7

You can use ||= operator to assign value if nil, e.g.:

network_stats["b"] ||= 1

Then you are sure that network_stats["b"] has value so simple increment by 1:

network_stats["b"] += 1

Final code:

network_stats["b"] ||= 1
network_stats["b"] += 1