{ console.log(b); let b = 20; }b before its declaration in the same block results in a ReferenceError.
What is the 'temporal dead zone'?
A). The period during which a variable is declared but not yet initialized
B). The time when the variable is accessible throughout the program
C). The period after variable initialization
D). None of the above
What is the difference between let and var in terms of scope?
A). let is function scoped, var is block scoped
B). let is block scoped, var is function scoped
C). Both are function scoped
D). Both are block scoped
What will be the output of the following code?
let e = 25; function test() { console.log(e); let e = 30; } test();A). 25
B). 30
C). undefined
D). ReferenceError
What will be the output of the following code?
let c = 5; { let c = 10; console.log(c); }A). 5
B). 10
C). ReferenceError
D). undefined
What is the scope of a variable declared with let inside a loop?
A). Global scope
B). Function scope
C). Block scope
D). Module scope
Which of the following is true about let declarations?
A). They are hoisted and initialized at the top of their scope
B). They are hoisted but not initialized
C). They are not hoisted at all
D). They are function scoped
How can you avoid variable hoisting issues with let?
A). Declare variables at the bottom of the code
B). Use var instead
C). Declare variables at the top of their scope
D). Do not declare variables
What happens when you try to re-declare a let variable in the same scope?
A). It reassigns the value
B). It throws a SyntaxError
C). It re-declares the variable
D). It throws a TypeError
What will be the output of the following code?
let i = 50; { let i = 55; console.log(i); } console.log(i);A). 50 50
B). 55 50
C). 50 55
D). ReferenceError
Where should let variables be declared to avoid TDZ issues?
A). At the top of the global scope
B). At the bottom of their block scope
C). At the top of their block scope
D). Anywhere in the code