Q
What is the purpose of the 'typeof' operator in JavaScript?

Answer & Solution

Answer: Option B
Solution:
The 'typeof' operator in JavaScript is used to check the data type of a variable or an expression. It returns a string indicating the data type of the operand. For example, 'typeof 42' will return 'number', and 'typeof 'hello'' will return 'string'. Therefore, option B correctly explains the purpose of the 'typeof' operator in JavaScript.
Related Questions on Average

What is the purpose of the 'this' keyword in JavaScript?

A). To refer to the current HTML element

B). To refer to the current JavaScript file

C). To refer to the current object

D). To refer to the current function

How can you convert a string to a number in JavaScript?

A). parseInt('10')

B). parseFloat('10.5')

C). Number('10')

D). All of the above

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

A). var x = 10;

B). let x = 10;

C). const x = 10;

D). variable x = 10;

How can you comment a single line of code in JavaScript?

A). // This is a comment

B). <!-- This is a comment -->

C). /* This is a comment */

D). ''' This is a comment '''

Which statement correctly declares a JavaScript object?

A). let person = {name: 'John', age: 30};

B). const person = ('name' => 'John', 'age' => 30);

C). const person = ['name', 'John', 'age', 30];

D). var person = {name: 'John', age: 30};

What is the purpose of the 'continue' statement in a JavaScript loop?

A). To exit the loop

B). To skip the current iteration

C). To restart the loop

D). To execute the loop body again

Which statement correctly declares a JavaScript function?

A). function greet() {}

B). const greet = function() {}

C). const greet = () => {}

D). const greet = {}

How can you prevent a JavaScript function from executing immediately?

A). Using async/await

B). Using the defer attribute in HTML script tag

C). Wrapping the function in parentheses

D). Using the setTimeout function

Which method is used to remove the last element from a JavaScript array?

A). colors.pop();

B). colors.removeLast();

C). colors.splice(-1, 1);

D). colors.deleteLast();

How can you add a new element to the end of a JavaScript array?

A). colors.push('blue');

B). colors.add('blue');

C). colors.insert('blue', colors.length);

D). colors[colors.length] = 'blue';