如何爲散列中的每個鍵添加前綴？

Question

我在我的哈希以下鍵：

address, postcode 

我要了「shipping_」前綴添加到每個人，這樣他們就變成：

shipping_address, shipping_postcode 

代替。我怎樣才能做到這一點？

Answer 1

hsh1 = {'address' => "foo", 'postcode' => "bar"} 
hsh2 = Hash[hsh1.map{|k,v| [k.dup.prepend("shipping_"),v]}] 
p hsh2 
# >> {"shipping_address"=>"foo", "shipping_postcode"=>"bar"} 

更新

hsh1 = {'address' => "foo", 'postcode' => "bar"} 
hsh2 = Hash[hsh1.map{|k,v| ["shipping_#{k}",v]}] 
p hsh2 
# >> {"shipping_address"=>"foo", "shipping_postcode"=>"bar"} 

Answer 2

如果你想破壞性做到這一點，這是一個簡短的方式：

hash.keys.each{|k| hash.store("shipping_#{k}", hash.delete(k))}