Method_missing for catch-all in Ruby - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to define a method that catches calls to undefined methods.

Ruby

def [1](method_name)
  puts "You called #{method_name}!"
end

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Amethod_missing

Bundefined_method

Cmissing_method

Dcatch_all

Attempts:

3 left

💡 Hint

Common Mistakes

Using a method name other than 'method_missing' will not catch undefined methods.

The method_missing method in Ruby is called when an undefined method is invoked on an object.

2fill in blank

medium

Complete the code to print the name of the missing method and its arguments.

Ruby

def method_missing(method_name, *[1])
  puts "Called #{method_name} with #{args.inspect}"
end

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Aargs

Bparams

Carguments

Dvalues

Attempts:

3 left

💡 Hint

Common Mistakes

Using a variable name other than 'args' without updating the code inside the method.

The splat operator *args collects all arguments passed to the missing method into an array named args.

3fill in blank

hard

Fix the error in the method_missing definition to correctly handle missing methods with arguments.

Ruby

def method_missing(method_name, [1])
  puts "Missing method: #{method_name}"
end

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Aparams

Bargs

C*args

D&block

Attempts:

3 left

💡 Hint

Common Mistakes

Omitting the splat operator causes argument errors when multiple arguments are passed.

The splat operator *args is needed to capture any number of arguments passed to the missing method.

4fill in blank

hard

Fill both blanks to define method_missing that prints method name and block presence.

Ruby

def method_missing(method_name, *args, &[1])
  if [2]
    puts "Block given to #{method_name}"
  else
    puts "No block given to #{method_name}"
  end
end

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Ablock

Bargs

Cblock_given?

Dmethod_name

Attempts:

3 left

💡 Hint

Common Mistakes

Not capturing the block argument or not checking for block presence correctly.

The &block captures an optional block passed to the method. The block_given? method checks if a block was provided.

5fill in blank

hard

Fill all three blanks to define method_missing that logs method name, arguments, and returns a default message.

Ruby

def method_missing([1], *[2], &block)
  puts "Called #{method_name} with #{args.inspect}"
  "Default response for #[3]"
end

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Amethod_name

Bargs

Dparams

Attempts:

3 left

💡 Hint

Common Mistakes

Using inconsistent variable names or missing the splat operator for arguments.

The method parameters are method_name for the method called, *args for arguments, and &block for an optional block. The method returns a default string including the method name.