What is the primary advantage of using block scope in JavaScript?
A). Reducing code size
B). Preventing variable hoisting
C). Avoiding global variables
D). Improving performance
Which keyword is used to declare block-scoped variables in JavaScript?
A). var
B). let
C). const
D). block
Which of the following best describes the behavior of JavaScript's const keyword?
A). It prevents variables from being redeclared
B). It ensures variables cannot be reassigned
C). It provides global scope for variables
D). It allows variables to change their data type
What will be the output of the code above?
A). 10
B). 20
C). Error
D). Undefined
In JavaScript, const variables are not hoiste What does this mean?
A). They are hoisted to the top of the block
B). They cannot be used before declaration
C). They are accessible in nested scopes
D). They are block-scoped variables
What will be the output of the code above?
A). 30
B). 31
C). Error
D). Undefined
What is the benefit of using const over var in JavaScript?
A). const variables have function scope
B). const variables are hoisted to the top
C). const variables prevent accidental reassignments
D). const variables can be used anywhere
What will be the output of the code above?
A). 30
B). 31
C). TypeError
D). Undefined
Which of the following is NOT an example of a block in JavaScript?
A). Function body
B). if statement body
C). while loop body
D). Object literal
What will be logged to the console after executing the code above?
A). ['red', 'blue', 'green', 'yellow']
B). ['red', 'blue', 'green']
C). ['yellow']
D). Error