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Remember when we mentioned that symbols are awesome for referencing method names? Well, .respond_to? takes a symbol and returns true if an object can receive that method and false otherwise. For example,
would return true, since you can call .push on an array object. However,
would return false, since you can’t turn an array into a symbol.
Instructions
1.
Rather than checking to see if our age variable is an integer, check to see if it will .respond_to? the .next method. (.next will return the integer immediately following the integer it’s called on, meaning 4.next will return 5.)