Which of the following correctly describes variable hoisting with 'let' and 'const'?
A). Both 'let' and 'const' declarations are not hoisted
B). Only 'let' declarations are hoisted
C). Only 'const' declarations are hoisted
D). Both 'let' and 'const' declarations are hoisted but not initialized
What happens if you try to redeclare a 'const' variable in JavaScript?
A). It will throw an error
B). The variable is overwritten
C). The variable is converted to 'let'
D). The program continues with a warning
Which of the following correctly describes variable hoisting with 'var'?
A). 'var' declarations are not hoisted
B). Only the variable declaration is hoisted, not the initialization
C). Both declaration and initialization are hoisted
D). Only in strict mode 'var' declarations are hoisted
What will happen if you declare a 'let' variable inside a block and try to access it outside the block?
A). It will return undefined
B). It will throw a ReferenceError
C). It will return null
D). It will be accessible outside the block
How does the scope of 'var' differ from 'let' and 'const' inside a function?
A). 'var' is block-scoped, 'let' and 'const' are function-scoped
B). 'var', 'let', and 'const' are all block-scoped
C). 'var' is function-scoped, 'let' and 'const' are block-scoped
D). 'var' and 'let' are block-scoped, 'const' is function-scoped
Given 'var a = 1; var a = 2;', what is the value of 'a' after these statements execute?
A). 1
B). 2
C). Undefined
D). Syntax Error
What will happen if you try to use a variable before declaring it with 'let'?
A). It will return undefined
B). It will return null
C). It will throw a ReferenceError
D). It will return NaN
What will be the result of executing 'let x = 1; let x = 2;' in the same scope?
A). x will be 1
B). x will be 2
C). Syntax Error
D). Runtime Error
Why is it recommended to use 'let' and 'const' over 'var' in modern JavaScript?
A). 'let' and 'const' are function-scoped
B). 'let' and 'const' prevent variable hoisting
C). 'let' and 'const' are block-scoped, reducing potential errors
D). 'let' and 'const' are faster
Can you redeclare a 'var' variable in a different scope without error?
A). Yes
B). No
C). Only in strict mode
D). Only if the variable is not initialized