Answer & Solution
Answer: Option B
Solution:
Due to hoisting, the variable a is declared at the top but not initialized, so it is undefined.
Q
What will be the output of the following code?
console.log(a); var a = 10;
Related Questions on Average
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
Which of the following is a valid variable name in JavaScript?
A). 2name
B). _name
C). #name
D).
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 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 is used to declare a variable in JavaScript?
A). var
B). let
C). const
D). All of the above
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 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
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
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
Which of the following is NOT a valid variable name in JavaScript?
A). myVar
B). $myVar
C). _myVar
D). 123myVar