SyntaxError

SyntaxError is raised when Ruby's parser encounters code that doesn't conform to Ruby's syntax rules. This happens at parse time, before the code runs.

Common causes

• Missing end keyword for blocks/methods/classes
• Unmatched parentheses, brackets, or quotes
• Invalid method or variable names
• Missing commas in arrays/hashes
• Invalid string interpolation syntax

How to fix it

• Use an editor with syntax highlighting
• Run ruby -c file.rb to check syntax
• Use a linter like RuboCop
• Check for matching pairs: (), [], {}, do/end
• Review recent changes for typos

Example

# Error examples
def greet(name)
  puts "Hello, #{name}!"
# Missing 'end' => SyntaxError

# Unmatched brackets
array = [1, 2, 3  # => SyntaxError: unexpected end-of-input

# Fix
def greet(name)
  puts "Hello, #{name}!"
end

array = [1, 2, 3]

Related errors