Enums in Blockchain / Solidity - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to declare an enum named Color with values Red, Green, and Blue.

Blockchain / Solidity

[1] Color {
    Red,
    Green,
    Blue
}

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Aclass

Bcontract

Cstruct

Denum

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'class' instead of 'enum' to declare an enum.

Using 'struct' which is for data structures, not enums.

In blockchain languages like Solidity, enum is used to declare an enumeration type.

2fill in blank

medium

Complete the code to assign the enum value Green to the variable favoriteColor.

Blockchain / Solidity

Color favoriteColor = Color.[1];

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ABlue

BGreen

CRed

DYellow

Attempts:

3 left

💡 Hint

Common Mistakes

Using a color not declared in the enum like 'Yellow'.

Forgetting to prefix with the enum type name.

To assign an enum value, use the enum type name followed by a dot and the value name.

3fill in blank

hard

Fix the error in the code to correctly compare if the variable currentStatus equals Status.Active.

Blockchain / Solidity

if (currentStatus [1] Status.Active) {
    // do something
}

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A==

B=

C!=

D=>

Attempts:

3 left

💡 Hint

Common Mistakes

Using single equals = which assigns instead of compares.

Using arrow => which is not a comparison operator.

Use == to compare enum values for equality.

4fill in blank

hard

Fill both blanks to create a function that returns true if the input status is Pending.

Blockchain / Solidity

function isPending(Status status) public pure returns (bool) {
    return status [1] Status.[2];
}

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A==

B!=

CPending

DActive

Attempts:

3 left

💡 Hint

Common Mistakes

Using '!=' instead of '==' which would check for inequality.

Using the wrong enum value like 'Active' instead of 'Pending'.

The function compares the input status with Status.Pending using the equality operator ==.

5fill in blank

hard

Fill all three blanks to create a mapping from address to Status and a function to set the status.

Blockchain / Solidity

mapping(address => Status) public [1];

function setStatus(address user, Status newStatus) public {
    [2][user] = [3];
}

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AuserStatus

BnewStatus

Cstatus

Duser

Attempts:

3 left

💡 Hint

Common Mistakes

Using different names for the mapping in declaration and assignment.

Assigning the wrong variable instead of newStatus.

The mapping is named userStatus. The function sets userStatus[user] to newStatus.