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

Answer & Solution

Answer: Option B
Solution:
In modern JavaScript, 'let' and 'const' are preferred over 'var' due to block scoping and better variable management. 'var' is function-scoped, while 'let' and 'const' are block-scoped, making them safer and more predictable in terms of variable scope. Therefore, option B is the correct way to declare a variable 'x' with an initial value of 10.
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

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

A). Type and value equality

B). Type equality only

C). Value equality only

D). Reference equality

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

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

A). To check if a variable is defined

B). To check the data type of a variable

C). To assign a data type to a variable

D). To increment the value of a variable

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 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 'return' statement in a JavaScript function?

A). To end the function execution

B). To return a value from the function

C). To print a value to the console

D). To declare a variable

Which statement correctly declares a JavaScript arrow function?

A). const add = (a, => a + b;

B). function add(a, { return a + b; }

C). const add = function(a, { return a + b; }

D). let add = function(a, { return a + b; };

Which statement correctly declares a JavaScript array?

A). let colors = ['red', 'green'];

B). const colors = {'red', 'green'};

C). const colors = ['red', 'green'];

D). var colors = ('red', 'green');

What is the purpose of the 'break' statement in a JavaScript switch case?

A). To continue to the next case

B). To exit the switch statement

C). To restart the switch statement

D). To execute the default case