Salesforce JavaScript Developer Practice Exam

Given the code: const myDt = new Date(); console.log(myDt + 10); what will be the output?

1. A number representing milliseconds

2. Today's date, plus 10 days

3. An error

4. Only '10'

The correct answer is: Today's date, plus 10 days

The output of the code is determined by how JavaScript handles the addition of a number to a Date object when the `+` operator is used. In JavaScript, when you attempt to concatenate a Date object with a number using the `+` operator, the Date object is first converted to a string representation of the date. When the code `console.log(myDt + 10);` is executed, the Date object `myDt` is converted to a string that represents the current date and time. Then, the `10` is treated as a string and concatenated to this date string. As a result, the output will not represent a date calculation, such as adding 10 days, but rather it will simply show the string representation of the date followed by the number `10`. Therefore, given how JavaScript handles the addition of a Date object and a number, the output would actually be a string containing the current date and time with `10` appended to it. The provided answer of "Today's date, plus 10 days" does not accurately reflect this behavior. The correct interpretation of the output focuses on the string concatenation rather than any date arithmetic.