Which assignment will fail?

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

A). 5

B). 10

C). 15

D). 20

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

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

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 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