In Ruby, how do I check if method "foo=()" is defined?

In Ruby, how do I check if method "foo=()" is defined?

ruby syntax-error

ruby

Why does the expression (true == true == true) produce a syntax error?

ruby syntax-error operators operator-precedence associativity

ruby

Hash syntax in Ruby [duplicate]

ruby hash syntax-error

ruby

Rails 3.2 Postgres Save Error "ActiveRecord::StatementInvalid: PG::Error: ERROR: Syntax error near 'T' at position 5"

ruby-on-rails ruby postgresql syntax-error

ruby

syntax error, unexpected ',', expecting ')'

ruby syntax-error ruby-1.9

ruby