[Solved] Given this code, what will obj.foo.bar output?class CatchAll def method_missing(name, *args) puts "Called #{name} with #{args.inspect}" self end end obj = CatchAll.new obj.foo.bar | Ruby

Ruby - Metaprogramming Fundamentals

Given this code, what will obj.foo.bar output?

class CatchAll
  def method_missing(name, *args)
    puts "Called #{name} with #{args.inspect}"
    self
  end
end
obj = CatchAll.new
obj.foo.bar

ACalled bar with []

BCalled foo with []

CCalled foo with []\nCalled bar with []

DNoMethodError for bar

Step-by-Step Solution

Solution:

Step 1: Analyze obj.foo call
Since foo is missing, method_missing prints "Called foo with []" and returns self.
Step 2: Analyze .bar call on returned self
bar is also missing, so method_missing prints "Called bar with []" and returns self again.
Final Answer:
Called foo with []\nCalled bar with [] -> Option C
Quick Check:
method_missing chaining returns self, prints each call [OK]

Quick Trick: Return self in method_missing to allow chaining [OK]

Common Mistakes:

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Given this code, what will obj.foo.bar output?