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 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 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
What is the result of let x = 10; x -= 3;?
A). 7
B). 13
C). 10
D). 3
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 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 };
What is the equivalent of x *= 4?
A). x = x + 4
B). x = x / 4
C). x = x * 4
D). x = 4
What will be the value of x after the following code: let x = 10; x += 5;
A). 5
B). 10
C). 15
D). 20
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