JavaScript Quiz

What will the following code print to the console?

• developer

• "developer"

• Naomi

• "Naomi"

Answer explanation

The code will print "Naomi" to the console because the string is enclosed in double quotes, indicating a literal string.

Which of the following is a non-primitive data type in JavaScript?

• Number

• String

• Boolean

• Array

Answer explanation

The non-primitive data type in JavaScript is Array. Number, String, and Boolean are all primitive data types.

How do you access the first value in an array named 'rows' in JavaScript?

• rows[1]

• rows[0]

• rows.first

• rows[2]

Answer explanation

To access the first value in an array named 'rows' in JavaScript, you use 'rows[0]' since array indexing starts at 0.

Which keyword should be used to declare variables that should not be reassigned in JavaScript?

• A) let

• B) var

• C) const

• D) static

Answer explanation

The keyword 'const' should be used to declare variables that should not be reassigned in JavaScript.

What does the .log() method do in JavaScript?

• A) Adds a value to the end of an array

• B) Removes the first element from an array

• C) Logs a message to the console

• D) Removes the last element from an array

Answer explanation

The .log() method in JavaScript logs a message to the console, making option C the correct choice.

What does the less than operator (<) allow you to check?

• If the value on the left is greater than the value on the right

• If the value on the left is equal to the value on the right

• If the value on the left is less than the value on the right

• If the value on the right is less than the value on the left

Answer explanation

The less than operator (<) allows you to check if the value on the left is less than the value on the right.

What will the expression count < 3 evaluate to if count is 4?

• false

• true

• undefined

• null

Answer explanation

The expression count < 3 will evaluate to false if count is 4 because 4 is not less than 3. Therefore, the correct answer is false.

What is the output of the following code: `hello = hello + " World"`?

• "hello"

• "World"

• "hello World"

• "hello + World"

Answer explanation

The correct output is 'hello World' because the code concatenates 'hello' with ' World', resulting in 'hello World'.

What is the output of the following code: `const activity = "Code! "; activity.repeat(3);`?

• "Code!"

• "Code! Code!"

• "Code! Code! Code!"

• "Code! Code! Code! Code!"

Answer explanation

The output of the code is 'Code! Code! Code!' because the repeat() method repeats the string 'Code!' three times.

How many parameters can a JavaScript function have?

• Only one.

• Two.

• As many as needed.

• None.

Answer explanation

A JavaScript function can have as many parameters as needed, making the correct answer choice 'As many as needed.'