What does const do in JavaScript?

Can a constant objects properties be changed?

A). Yes

B). No

C). Only if redeclared

D). Only with special methods

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

How to increment a variable count by 1?

A). count + 1

B). count += 1

C). count =+ 1

D). count = 1

What will let x = 5, y = 10; [x, y] = [y, x]; do?

A). Nothing

B). Throws an error

C). Swaps values of x and y

D). None of the above

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;

What is the outcome of let x = 8; x %= 3;?

A). 1

B). 2

C). 3

D). 5

Which operator assigns a remainder to a variable?

A). +=

B). -=

C). *=

D). %=

What will be the result of let { a, b } = { a: 3, b: 4 };?

A). a is 4, b is 3

B). a is 3, b is 4

C). a is undefined, b is undefined

D). a is null, b is null

What does let { a: alpha, b: beta } = { a: 1, b: 2 }; do?

A). Creates variables alpha and beta with values 1 and 2

B). Creates variables a and b with values 1 and 2

C). Throws an error

D). Assigns default values

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