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
What error is thrown when attempting to redeclare a 'const' variable?
A). TypeError
B). ReferenceError
C). SyntaxError
D). RangeError
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
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 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
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 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 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
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
How does 'let' differ from 'var' in terms of scope?
A). 'let' is function-scoped, 'var' is block-scoped
B). Both 'let' and 'var' are block-scoped
C). 'let' is block-scoped, 'var' is function-scoped
D). Both 'let' and 'var' are function-scoped