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 equivalent of x *= 4?
A). x = x + 4
B). x = x / 4
C). x = x * 4
D). x = 4
How to use destructuring to extract properties from an object?
A). { a, b } = { a: 1, b: 2 }
B). let { a, b } = { a: 1, b: 2 };
C). let a, b = { a: 1, b: 2 };
D). let (a, b) = { a: 1, b: 2 };
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
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 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
Which of the following is the assignment operator in JavaScript?
A). =
B). ==
C). ===
D). !=
Can a constant objects properties be changed?
A). Yes
B). No
C). Only if redeclared
D). Only with special methods
What will const x = { a: 1 }; x.a = 2; do?
A). Throw an error
B). Change x.a to 2
C). Change x to 2
D). Do nothing
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