Hoisting with let and const in Javascript - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to declare a variable with block scope using let.

Javascript

let [1] = 5;
console.log(x);

Drag options to blanks, or click blank then click option'

Avar

Bx

Cconst

Dy

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'var' instead of a variable name.

Using 'const' as a variable name.

Using an undeclared variable name.

The variable x is declared using let, which has block scope and is hoisted but not initialized.

2fill in blank

medium

Complete the code to declare a constant variable.

Javascript

const [1] = 10;
console.log(value);

Drag options to blanks, or click blank then click option'

Avalue

Blet

Cvar

Dnum

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'var' or 'let' instead of 'const'.

Using a different variable name than in the console.log.

The constant variable value is declared with const and cannot be reassigned.

3fill in blank

hard

Fix the error in accessing a let variable before declaration.

Javascript

console.log([1]);
let a = 3;

Drag options to blanks, or click blank then click option'

Aa

Bb

C3

Dlet

Attempts:

3 left

💡 Hint

Common Mistakes

Using a variable name not declared.

Trying to access the variable before declaration.

Accessing a before its declaration causes a ReferenceError due to the temporal dead zone of let.

4fill in blank

hard

Fill both blanks to create a block-scoped variable and log it.

Javascript

{
  [1] x = 7;
  console.log([2]);
}

Drag options to blanks, or click blank then click option'

Alet

Bvar

Cx

Dy

Attempts:

3 left

💡 Hint

Common Mistakes

Using var which is function-scoped.

Logging a variable name not declared.

Using let declares a block-scoped variable x, which can be logged inside the block.

5fill in blank

hard

Fill all three blanks to declare a constant and log its value.

Javascript

const [1] = 20;
function show() {
  console.log([2]);
}
show();
console.log([3]);

Drag options to blanks, or click blank then click option'

API

Dradius

Attempts:

3 left

💡 Hint

Common Mistakes

Using different variable names in the blanks.

Using a variable not declared.

The constant PI is declared and logged inside and outside the function.