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 'let' variable in the same scope in JavaScript?
A). Yes
B). No
C). Only in strict mode
D). Only in non-strict mode
What does 'TDZ' stand for in the context of JavaScript?
A). Temporary Declaration Zone
B). Temporal Dead Zone
C). Temporary Dead Zone
D). Temporal Declaration Zone
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
Which of the following statements is true regarding redeclaring variables in JavaScript?
A). You can redeclare 'var' variables within the same scope without errors
B). You can redeclare 'let' variables within the same scope without errors
C). You can redeclare 'const' variables within the same scope without errors
D). None of the above
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
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
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 error is thrown when attempting to redeclare a 'const' variable?
A). TypeError
B). ReferenceError
C). SyntaxError
D). RangeError
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