julia では println() 内の変数では、$を使って、"," を減らす方が早いようだ

今さらですが、 println() 内の変数では、$を使って、"," を減らす方が早いようです。 

#1 
julia> @time for animal in ["dog", "cat", "mouse"]
           println(animal," is a mammal")
       end
dog is a mammal
cat is a mammal
mouse is a mammal
  0.000147 seconds (20 allocations: 848 bytes)

julia> @time for animal in ["dog", "cat", "mouse"]
           println("$animal is a mammal")
       end
dog is a mammal
cat is a mammal
mouse is a mammal
  0.000082 seconds (17 allocations: 864 bytes)

#2
julia> @time for (k, v) in Dict("dog" => "mammal", "cat" => "mammal", "mouse" => "mammal")
           println("$k is a $v")
       end
mouse is a mammal
cat is a mammal
dog is a mammal
  0.000082 seconds (23 allocations: 1.063 KiB)

julia> @time for (k, v) in Dict("dog" => "mammal", "cat" => "mammal", "mouse" => "mammal")
           println(k," is a ",v)
       end
mouse is a mammal
cat is a mammal
dog is a mammal
  0.000135 seconds (35 allocations: 1.234 KiB)
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