Dynamic typing in JavaScript - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to declare a variable with dynamic typing.

Javascript

let value = [1];

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

A"hello"

Bnull

Ctrue

D42

Attempts:

3 left

💡 Hint

Common Mistakes

Forgetting quotes around strings.

Using undefined variables.

In JavaScript, variables can hold any type. Here, we assign a string "hello" to the variable.

2fill in blank

medium

Complete the code to change the variable type dynamically.

Javascript

let data = 10;
data = [1];

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

A"twenty"

B20

Cfalse

Dnull

Attempts:

3 left

💡 Hint

Common Mistakes

Assigning a number without quotes when a string is needed.

Using boolean instead of string.

JavaScript allows changing the type of a variable. Here, we change from number 10 to string "twenty".

3fill in blank

hard

Fix the error by completing the code to convert a number to a string.

Javascript

let num = 5;
let str = num[1];

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

A* 2

B+ 1

C.toString()

D- 3

Attempts:

3 left

💡 Hint

Common Mistakes

Using arithmetic operators instead of conversion methods.

Forgetting parentheses after method name.

The toString() method converts a number to a string in JavaScript.

4fill in blank

hard

Fill both blanks to create a variable that changes from boolean to string.

Javascript

let flag = [1];
flag = [2];

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

Atrue

B"true"

Cfalse

D"false"

Attempts:

3 left

💡 Hint

Common Mistakes

Using quotes for boolean values initially.

Not using quotes when changing to string.

Initially, flag is a boolean true. Then it changes to the string "true".

5fill in blank

hard

Fill all three blanks to create a variable that changes from number to string and then to boolean.

Javascript

let val = [1];
val = [2];
val = [3];

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

A100

B"100"

Cfalse

Dtrue

Attempts:

3 left

💡 Hint

Common Mistakes

Mixing quotes for numbers.

Using wrong boolean values.

The variable val starts as number 100, then changes to string "100", and finally to boolean false.