Salesforce JavaScript Developer Practice Exam

What is the log output for the following code: console.log(JSON.stringify([new Number(3), new String('false'), new Boolean(false)]));

1. A String with the value of "[3,"false",false]"

2. A String with the value of "[3,"false",true]"

3. A String with the value of "[3,false,false]"

4. An Object representation

The correct answer is: A String with the value of "[3,"false",false]"

The log output for the provided code is indeed a string with the value of "[3,"false",false]". This result comes from how the `JSON.stringify` method handles different object types in JavaScript. When you pass the array containing instances of `Number`, `String`, and `Boolean` to `JSON.stringify`, it performs serialization on those objects. For instance: - The `new Number(3)` instance gets converted to the primitive value `3`. - The `new String('false')` instance is converted to the primitive string value `'false'`. - The `new Boolean(false)` instance converts to the primitive boolean value `false`. The `JSON.stringify` method specifically only captures the primitive values of these wrapper objects when converting them to a JSON string format. Therefore, the output correctly reflects the conversion of those wrapped values into a JSON-compatible format, resulting in the string "[3,"false",false]". This output illustrates an important aspect of JavaScript object behavior, particularly with wrapper types for primitives, and how JSON handles the serialization of these objects.