Which of the following is true about 'const' variables in JavaScript?

Which of the following is a valid variable name in JavaScript?

A). 2name

B). _name

C). #name

D).

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

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

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?

let a = 1; let b = 2; let c = a + b; console.log(c);

A). 12

B). 12

C). 3

D). NaN

Which keyword should be used to declare a block-scoped variable?

A). var

B). let

C). const

D). Both let and const

Which statement is true about variables in JavaScript?

A). They must be declared before use

B). They can only hold numbers

C). They are statically typed

D). They are strongly typed

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;

Which of the following is NOT a valid variable name in JavaScript?

A). myVar

B). $myVar

C). _myVar

D). 123myVar

Which of the following is true about variable naming conventions in JavaScript?

A). Variable names can start with a number

B). Variable names are case-insensitive

C). Variable names can include spaces

D). Variable names are case-sensitive