What will be the output of the following code?
let x; console.log(x);
A). null
B). undefined
C). 0
D). NaN
What is the difference between let and var?
A). let is function-scoped, var is block-scoped
B). let is block-scoped, var is function-scoped
C). Both are block-scoped
D). Both are function-scoped
What is the correct syntax for declaring a variable in JavaScript?
A). let myVar = 5;
B). myVar let = 5;
C). 5 = let myVar;
D). let = myVar 5;
What is hoisting in JavaScript?
A). Function call before declaration
B). Variable declared at the top
C). Variable and function declaration are moved to the top
D). Variable scope
Can variables declared with 'var' be redeclared in the same scope?
A). Yes
B). No
C). Only inside a function
D). Only inside a loop
What will be the output of the following code?
var a = 1; { var a = 2; } console.log(a);
A). 1
B). 2
C). undefined
D). ReferenceError
What will be the output of the following code?
var x = 5; var y = 6; var z = x + y;
A). 11
B). 11
C). 5
D). 6
Which of the following is a valid variable name in JavaScript?
A). 2name
B). _name
C). #name
D).
Which of the following will cause an error?
A). let a = 10; a = 20;
B). const a = 10; a = 20;
C). var a = 10; a = 20;
D). None of the above
What will be the output of the following code?
const a = 10; a = 20; console.log(a);
A). 10
B). 20
C). Error
D). undefined