How do you create a Ruby hash that automatically assigns a new empty array to any missing key and stores it in the hash?

hard📝 Application Q9 of 15

Ruby - Hashes

Ah = Hash.new { |hash, key| hash[key] = [] }

Bh = Hash.new([])

Ch = Hash.new([]); h.default = []

Dh = Hash.new { [] }

Step-by-Step Solution

Solution:

Step 1: Use block with Hash.new
Using a block allows assigning a new array for each missing key.
Step 2: Assign new array to missing key
The block sets hash[key] = [], storing the new array in the hash.
Final Answer:
h = Hash.new { |hash, key| hash[key] = [] } -> Option A
Quick Check:
Accessing missing keys returns unique arrays stored in hash [OK]

Quick Trick: Use block to assign new object per missing key [OK]

Common Mistakes:

MISTAKES

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