Answer & Solution
Answer: Option B
Solution:
Valid variable names can start with letters, $, or _ and cannot start with numbers or other special characters.
Q
Which of the following is a valid variable name in JavaScript?
Related Questions on Average
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 'const' variables in JavaScript?
A). They can be redeclared
B). They cannot be reassigned
C). They can be reassigned
D). They are always undefined
Which of the following is correct about variable scope in JavaScript?
A). var is block-scoped
B). let is function-scoped
C). const is block-scoped
D). All variables are global
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
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;
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?
const a = 10; a = 20; console.log(a);
A). 10
B). 20
C). Error
D). undefined
Which keyword should be used to declare a block-scoped variable?
A). var
B). let
C). const
D). Both let and const
What will be the output of the following code?
let x; console.log(x);
A). null
B). undefined
C). 0
D). NaN
What will be the output of the following code?
console.log(a); var a = 10;
A). 10
B). undefined
C). Error
D). null