20 MCQ on Declaring (Creating) JavaScript Variables in 2000 words with example. in excel format with Question in Col A, Option A in Col B, Option B in col C, Option C in col D, Option D in col e, Right Answer in col f, Solution with explanation in col g without sno and options a,b,c,d and put all html tags in special container

What is the outcome of console.log(typeof x); if x is declared but not initialized in JavaScript?

A). a. Undefined

B). b. Null

C). c. Error

D). d. Object

What will happen if you try to reassign a value to a constant declared with const in JavaScript?

A). a. It will throw an error

B). b. It will silently ignore the assignment

C). c. It will convert the variable to let

D). d. It will convert the variable to var

Which of the following statements is true about the let keyword in JavaScript?

A). a. Variables declared with let have global scope

B). b. Variables declared with let are block-scoped

C). c. let is used to declare constants

D). d. let is used to declare functions

What will console.log(a); output if a is declared outside a function but inside a block using let in JavaScript?

A). a. It will output the value of a

B). b. It will throw an error

C). c. It will output undefined

D). d. It

What is the difference between var and let in terms of scope in JavaScript?

A). a. Both have function scope

B). b. Both have block scope

C). c. var has block scope, let has function scope

D). d. var has function scope, let has block scope

What does hoisting refer to in JavaScript variable declarations?

A). a. Declaring a variable multiple times

B). b. Initializing a variable before declaring

C). c. Moving variable declarations to the top

D). d. Using undeclared variables

What does hoisting refer to in JavaScript variable declarations?

A). a. Declaring a variable multiple times

B). b. Initializing a variable before declaring

C). c. Moving variable declarations to the top

D). d. Using undeclared variables

Which of the following variable names is valid in JavaScript?

A). a. my variable

B). b. _variable

C). c. 3variable

D). d. variable$

What is the purpose of using the const keyword in JavaScript?

A). a. To declare variables with function scope

B). b. To declare variables with block scope

C). c. To declare constants with immutable values

D). d. To declare objects in JavaScript

What will happen if you try to reassign a value to a constant declared with const in JavaScript?

A). a. It will throw an error

B). b. It will silently ignore the assignment

C). c. It will convert the variable to let

D). d. It will convert the variable to var