Answer & Solution
i due to let.
for (let i = 0; i < 3; i++) { setTimeout(() => console.log(i), 0); }
i due to let.
What will be the output of the following code?
let d; console.log(d); d = 15;
A). undefined
B). 15
C). null
D). ReferenceError
Which statement about let and const is correct?
A). Both are block scoped, but only let can be re-assigned
B). Both are block scoped, but only const can be re-assigned
C). Only const is block scoped
D). Both are not block scoped
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 will be the output of the following code?
console.log(a); let a = 10;
A). undefined
B). 10
C). null
D). ReferenceError
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
In which scope are let variables hoisted?
A). Function scope
B). Block scope
C). Global scope
D). Module scope
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 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
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
What will be the output of the following code?
{ console.log(b); let b = 20; }
A). 20
B). undefined
C). null
D). ReferenceError