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 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
Which of the following is the assignment operator in JavaScript?
A). =
B). ==
C). ===
D). !=
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 const do in JavaScript?
A). Declares a block-scoped variable
B). Declares a constant value
C). Declares a global variable
D). Declares a function
Which operator assigns a remainder to a variable?
A). +=
B). -=
C). *=
D). %=
What is the result of let x = 10; x -= 3;?
A). 7
B). 13
C). 10
D). 3
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 outcome of let x = 8; x %= 3;?
A). 1
B). 2
C). 3
D). 5