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 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
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
Can a constant objects properties be changed?
A). Yes
B). No
C). Only if redeclared
D). Only with special methods
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
What is the result of let x = 10; x -= 3;?
A). 7
B). 13
C). 10
D). 3
What is the equivalent of x *= 4?
A). x = x + 4
B). x = x / 4
C). x = x * 4
D). x = 4
Which of these correctly assigns values to variables using array destructuring?
A). [x, y, z] = [1, 2, 3]
B). [1, 2, 3] = [x, y, z]
C). let [x y z] = [1 2 3];
D). (x, y, z) = [1, 2, 3];
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