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

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();

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

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

A). Type and value equality

B). Type equality only

C). Value equality only

D). Reference equality

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');

Which operator is used for strict inequality in JavaScript?

A). !==

B). !=

C). <>

D). /=

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};

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