Data Storage and Collection Quiz 1

What is the correct syntax to declare a variable in JavaScript?

• `var myVariable;`

• `variable myVariable;`

• `declare myVariable;`

• `v myVariable;`

Which method is used to add an element to the end of an array in JavaScript?

• `add()`

• `push()`

• `append()`

• `insert()`

Explain how you would store a collection of user data, such as names and ages, in JavaScript. Provide a code example.

• Use a string to concatenate names and ages.

• Use an array of objects, where each object contains a name and age property.

• Use a single object with names as keys and ages as values.

• Use separate arrays for names and ages.

What is the output of the following code snippet? ```javascript let data = [1, 2, 3]; data.push(4); console.log(data); ```

• `[1, 2, 3]`

• `[1, 2, 3, 4]`

• `[4, 1, 2, 3]`

• `Error`

Describe a strategy to efficiently search for a specific item in a large dataset stored in an array.

• Use a for loop to iterate through each element.

• Use the `find()` method for a direct search.

• Sort the array first, then use binary search.

• Use a while loop to check each element.

Which of the following is a way to convert a JSON string into a JavaScript object?

• `JSON.parse()`

• `JSON.stringify()`

• `JSON.convert()`

• `JSON.toObject()`

How can you remove the last element from an array in JavaScript?

• `array.removeLast()`

• `array.pop()`

• `array.delete()`

• `array.shift()`

Given a dataset of student scores, how would you calculate the average score using JavaScript?

• Add all scores and divide by the number of scores.

• Use the `average()` method on the array.

• Use a loop to find the maximum and minimum scores, then average them.

• Use the `reduce()` method to sum the scores, then divide by the length of the array.

What is the purpose of the `localStorage` object in JavaScript?

• To store data temporarily during a session.

• To store data that persists even after the browser is closed.

• To store data only while the page is open.

• To store data on the server.

How would you handle a situation where you need to store a large amount of data that exceeds the `localStorage` limit?

• Use `sessionStorage` instead.

• Store data in smaller chunks.

• Use IndexedDB for larger storage needs.

• Compress the data before storing.