Fix the error in this Ruby code that tries to assign a unique array to each missing key:

medium📝 Debug Q7 of 15

Ruby - Hashes

h = Hash.new([])
h[:a] << 1
puts h[:a].inspect

AChange to h = Hash.new({})

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

CAssign h.default = [] after creation

DUse h = Hash.new(nil) and check for nil

Step-by-Step Solution

Solution:

Step 1: Identify problem with shared default array
Using Hash.new([]) shares the same array for all missing keys.
Step 2: Use block to assign unique array per key
Hash.new { |hash, key| hash[key] = [] } creates a new array for each missing key.
Final Answer:
Use Hash.new { |hash, key| hash[key] = [] } instead -> Option B
Quick Check:
Block default creates unique objects per key [OK]

Quick Trick: Use block with hash default for unique objects per key [OK]

Common Mistakes:

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