Why am I getting an error: `ReferenceError: toUpperCase is not defined`?


#1

Question

Why am I getting an error: ReferenceError: toUpperCase is not defined?

Answer

Remember, the syntax for built-in methods is: "String".methodName(). This error means you likely tried it as: methodName("String"). Move the string outside and in front of the built-in method, add the period and you should be good to go.