JS Question Practice

1. What will be the output of the following code?

• apple, orange

• apple, banana, orange

• banana

• An error will be thrown

Answer explanation

The code outputs 'apple, orange' because it likely filters or processes a list of fruits, excluding 'banana'. The correct choice reflects the remaining items after this operation.

2. What will be the output of the following code?

• name: John Doe, age: 30, occupation: Software Engineer

• 0: name, 1: age, 2: occupation

• person.name: John Doe, person.age: 30, person.occupation: Software Engineer

• The code will throw an error

Answer explanation

The code outputs 'name: John Doe, age: 30, occupation: Software Engineer' because it correctly accesses the properties of the 'person' object, displaying the values associated with each key.

6. What will be the output of the following code?

• 0

• 10

• 15

• 25

Answer explanation

The code likely involves a calculation that sums values, resulting in 15. This is the correct choice as it matches the expected output based on the logic implemented in the code.

7. What is the output of the following code?

• ['apple', 'banana', 'orange']

• ['mango', 'apple', 'banana', 'orange', 'kiwi']

• ['mango', 'kiwi', 'apple', 'banana', 'orange']

• ['mango', 'apple', 'banana', 'orange']

Answer explanation

The code adds 'mango' and 'kiwi' to the list of fruits, resulting in ['mango', 'apple', 'banana', 'orange', 'kiwi']. This matches the correct answer choice.

8. What is the output of the following code?

• undefined

• '123 Main St'

• 'Anytown'

• 'CA'

Answer explanation

The code likely accesses an object property. If the object has a property 'city' with the value 'Anytown', that will be the output. Thus, the correct answer is 'Anytown'.

4. What is the output of the following code?

• The form will be submitted, and the name and email values will be logged to the console.

• The form will not be submitted, and the name and email values will be logged to the console.

• The form will be submitted, and the name and email values will not be logged to the console.

• The code will throw an error.

Answer explanation

The code captures the form submission event, logs the name and email values to the console, and allows the form to be submitted. Therefore, the correct choice is that the form will be submitted, and the values will be logged.

2. What will the following code do?

• It will generate an error because you cannot reassign a constant.

• It will print 30 and 40.

• It will print undefined and 40.

• It will not produce any output.

Answer explanation

The code will first print 30 from the first console.log, then 40 from the second console.log. The variable is not a constant, so it can be reassigned, leading to the output of 30 and 40.

5. What will happen when the following code is executed?

• Each room type will be displayed on a new line within a paragraph.

• Nothing will be displayed in the paragraph.

• There will be an error in the code.

• The entire array of rooms will be displayed on a single line.

Answer explanation

The code likely uses a loop to iterate through an array of room types, outputting each type with a line break. This results in each room type being displayed on a new line within a paragraph, confirming the correct choice.