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
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
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 happens when you redeclare a variable with 'var' inside a function?
A). The variable is overwritten
B). The variable declaration is ignored
C). It throws an error
D). The function's scope is reset
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
Which of the following statements about 'let' and 'const' is false?
A). Both 'let' and 'const' are block-scoped
B). Both 'let' and 'const' cannot be redeclared in the same scope
C). 'let' can be reassigned, 'const' cannot
D). Both 'let' and 'const' can be redeclared in different scopes
What is the result of redeclaring a variable with 'var' in the same scope in JavaScript?
A). Syntax Error
B). The variable is overwritten
C). The variable remains unchanged
D). The program crashes
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
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
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