Quick Answer

Handle undefined method calls on Arrays.

Understanding the Issue

This error occurs when calling non-existent methods on Array objects, often due to typos or incorrect assumptions about array contents.

The Problem

This code demonstrates the issue:

Ruby Error 
arr = [1, 2, 3]
arr.first_name # Error

The Solution

Here's the corrected code:

Ruby Fixed 
# Solution 1: Check method existence
if arr.respond_to?(:first_name)
  arr.first_name
end

# Solution 2: Verify array contents
arr.each do |item|
  if item.respond_to?(:name)
    puts item.name
  end
end

# Solution 3: Type checking
first_item = arr.first
if first_item.is_a?(User)
  puts first_item.name
end

Key Takeaways

Verify array methods and contents before calling methods.