Answer & Solution
Answer: Option a
Solution:
When a variable is declared but not initialized, its type is undefined in JavaScript. The correct option is a. Undefined.
Q
What is the outcome of console.log(typeof x); if x is declared but not initialized in JavaScript?
Related Questions on Average
Which keyword is used to declare a variable that cannot be reassigned in JavaScript?
A). a. var
B). b. let
C). c. const
D). d. mutable
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
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 keyword is used to declare variables in JavaScript?
A). a. var
B). b. const
C). c. let
D). d. def
Which keyword is used to declare a variable that cannot be reassigned in JavaScript?
A). a. var
B). b. let
C). c. const
D). d. mutable
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
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 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
Which of the following variable names is valid in JavaScript?
A). a. my variable
B). b. _variable
C). c. 3variable
D). d. variable$