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

Which statement correctly declares a JavaScript function?

A). function greet() {}

B). const greet = function() {}

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

D). const greet = {}

How do you access the last element of a JavaScript array?

A). colors[colors.length - 1];

B). colors.last();

C). colors[-1];

D). colors.getLast();

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 does the '===' operator check in JavaScript?

A). Type and value equality

B). Type equality only

C). Value equality only

D). Reference equality

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

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();

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

What is the purpose of the 'constructor' method in a JavaScript class?

A). To create new instances of the class

B). To initialize class properties

C). To define class methods

D). To define class inheritance

How do you concatenate strings in JavaScript?

A). Using the + operator

B). Using the - operator

C). Using the * operator

D). Using the / operator

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