How to use destructuring to extract properties from an object?

What does the assignment operator = do in JavaScript?

A). Compares two values

B). Assigns a value to a variable

C). Checks for equality

D). None of the above

What does const do in JavaScript?

A). Declares a block-scoped variable

B). Declares a constant value

C). Declares a global variable

D). Declares a function

What will be the output of let { a, b } = { a: 1, b: 2, c: 3 };?

A). a is 1, b is 2

B). a is 2, b is 3

C). a is 1, b is undefined

D). a is 3, b is undefined

What is the result of let x = 10; x -= 3;?

A). 7

B). 13

C). 10

D). 3

Can a constant objects properties be changed?

A). Yes

B). No

C). Only if redeclared

D). Only with special methods

Which of the following is the assignment operator in JavaScript?

A). =

B). ==

C). ===

D). !=

How do you assign default values in destructuring?

A). let { a, b } = { a: 1 };

B). let { a = 1, b = 2 } = {};

C). let [a, b] = [1, 2];

D). let { a, b } = { a: 1, b: 2 };

What will be the value of x after the following code: let x = 10; x += 5;

A). 5

B). 10

C). 15

D). 20

Which assignment will fail?

A). const x = 10; x = 20;

B). let y = 5; y = 10;

C). var z = 15; z = 30;

D). let a = { b: 2 }; a.b = 3;

How can you swap the values of two variables a and b in one line?

A). [a, b] = [b, a]

B). a = b, b = a

C). a == b, b == a

D). a === b, b === a