Salesforce JavaScript Developer Practice Exam

What does the rest parameter syntax (...args) do in a function?

1. It collects all arguments into a single string.

2. It creates an array from the provided arguments.

3. It limits the number of arguments to a function.

4. It checks the type of each argument provided.

The correct answer is: It creates an array from the provided arguments.

The rest parameter syntax, represented as (...args), is used in a function to gather any number of arguments into a single array. When a function is defined using this syntax, all additional arguments passed to the function are combined and stored as an array. This is particularly useful when the number of arguments is unknown or can vary. For instance, if you define a function like this: ```javascript function myFunction(...args) { console.log(args); } ``` And then call it with multiple arguments: ```javascript myFunction(1, 2, 3, 4); ``` The output will be an array containing those arguments: `[1, 2, 3, 4]`. This feature enhances flexibility, allowing developers to handle functions with variable-length arguments seamlessly. The other options do not accurately describe the behavior of the rest parameter syntax. Collecting all arguments into a single string would only occur if the developer manually concatenated the arguments or used some string manipulation method. Limiting the number of arguments is not a function of the rest parameter; it actually allows for any number of arguments to be passed. Finally, checking the type of each argument is not something that the rest parameter does; it merely collects the arguments