Salesforce JavaScript Developer Practice Exam

What will be the output when calling the added prototype method for Strings?

1. "Just give Lydia pizza already!"

2. TypeError: not a function

3. SyntaxError

4. undefined

The correct answer is: "Just give Lydia pizza already!"

When adding a prototype method for Strings in JavaScript, the output will depend on the implementation of that method. If the added prototype method is designed to return a string such as "Just give Lydia pizza already!" and is called on a string instance, it will indeed produce the specified output. Prototype methods are defined on the `String.prototype` object, enabling them to be accessed by all string instances. Such a method can be designed to return a predefined string when invoked. Therefore, if the string instance calls this method correctly, the output would be as specified in option A. In contrast, other potential outputs such as TypeError, SyntaxError, or undefined would arise under different circumstances, for instance, if the prototype method was not defined correctly, not called correctly, or didn’t return a value. Properly defining the method and calling it correctly ensures that the intended output is achieved.