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 is the outcome of let x = 8; x %= 3;?
A). 1
B). 2
C). 3
D). 5
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 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;
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
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 will be the value of x after the following code: let x = 10; x += 5;
A). 5
B). 10
C). 15
D). 20
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 };
Which operator assigns a remainder to a variable?
A). +=
B). -=
C). *=
D). %=