使用注入時可能分離出散列的鍵和值？

Question

當調用在紅寶石哈希each，你可以得到鍵和值很好地分離這樣的：

{ :a => 1, :b => 2, :c => 3 }.each do |key, value| 
    puts "key is #{key} and value is #{value}" 
end 

========================= 

key is :a and value is 1 
key is :b and value is 2 
key is :c and value is 3 
=> {:a=>1, :b=>2, :c=>3} 

然而，這似乎並沒有使用inject時工作。

{ :a => 1, :b => 2, :c => 3 }.inject(0) do |result, key, value| 
    puts "key is #{key} and value is #{value}" 
    result + value 
end 

========================= 

key is [:a, 1] and value is 
TypeError: nil can't be coerced into Fixnum 

在簡化上述例子我並不真正需要的鑰匙，所以我可以只調用hash.values.inject，但假設我兩者都需要，是有一個更清潔的方式來做到這一點比這可怕的bodge？

{ :a => 1, :b => 2, :c => 3 }.inject(0) do |result, key_and_value| 
    puts "key is #{key_and_value[0]} and value is #{key_and_value[1]}" 
    result + key_and_value[1] 
end 

Answer 1

它看起來像你需要：

{ :a => 1, :b => 2, :c => 3 }.inject(0) do |result, (key, value)| 
    puts "key is #{key} and value is #{value}" 
    result + value 
end