Answer & Solution
Answer: Option A
Solution:
Declaring a variable without 'var', 'let', or 'const' creates a global variable, which can lead to potential bugs.
Q
What will happen if you declare a variable without 'var', 'let', or 'const'?
Related Questions on Average
Which keyword is used for declaring variables that should not change?
A). var
B). let
C). const
D). all of the above
What will be the output of the following code: const d = 90; d = 100; console.log(d);
A). 90
B). 100
C). Error
D). undefined
What is the scope of a variable declared with 'let' inside a loop?
A). Global
B). Function
C). Loop block
D). Entire script
Which keyword allows block-scoped variable declaration?
A). var
B). let
C). const
D). Both B and C
Can you re-declare a variable using 'const' in the same scope?
A). Yes
B). No
C). Only in functions
D). Only in loops
What will be the output of the following code: console.log(a); var a = 50;
A). 50
B). undefined
C). Error
D). null
How does 'let' handle variable re-declaration in the same scope?
A). Allows it
B). Silently ignores
C). Throws an error
D). Creates a new variable
Which of the following statements is true about 'const'?
A). It allows re-declaration
B). It allows reassignment
C). It is block-scoped
D). It is function-scoped
What will be the output of the following code: var x = 5; var x = 10; console.log(x);
A). 5
B). 10
C). Error
D). undefined
How does 'let' differ from 'var' in terms of scope?
A). No difference
B). Function-scoped
C). Block-scoped
D). Global-scoped