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 a valid variable name in JavaScript?
A). 2name
B). _name
C). #name
D).
Which keyword is used to declare a variable in JavaScript?
A). var
B). let
C). const
D). All of the above
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 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?
var x = 5; var y = 6; var z = x + y;
A). 11
B). 11
C). 5
D). 6
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?
let a = 1; let b = 2; let c = a + b; console.log(c);
A). 12
B). 12
C). 3
D). NaN
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
What will be the output of the following code?
let x; console.log(x);
A). null
B). undefined
C). 0
D). NaN