5 Questions
Explain the purpose of the 'defined' operator in Ruby.
The 'defined' operator in Ruby is used to determine whether a given expression is defined or not. It returns a description string of the expression if it is defined, or 'nil' if the expression isn't defined.
What does 'defined.variable' return in Ruby?
The expression 'defined.variable' returns 'true' if the variable is initialized, along with a description string of the variable type, such as 'local-variable' or 'global-variable'. If the variable is not defined, it returns 'nil'.
How is the 'defined' operator used to check if a method is defined in Ruby?
The 'defined' operator is used with the method name, such as 'defined.method_name', to check if a method is defined. It returns 'true' along with the description string 'method' if the method is defined, or 'nil' if the method is not defined.
How does the 'defined.yield' operator work in Ruby?
The 'defined.yield' operator in Ruby returns 'true' if a code block has been passed, along with the string 'yield'. If no block has been passed, it returns 'nil'.
What does 'defined.super' indicate in Ruby?
In Ruby, 'defined.super' returns 'super' if a method exists that can be called with 'super'. If the method cannot be called with 'super', it returns 'nil'.
Test your knowledge of Ruby's defined operator and its various usages with this quiz. Learn how to use the defined operator to check if a variable is initialized and explore its different applications in Ruby programming.
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