Structs in Blockchain / Solidity - Mini Project: Build & Apply

Working with Structs in Blockchain

📖 Scenario: You are building a simple blockchain application that stores information about digital assets. Each asset has a name, an owner, and a value. You will use structs to organize this data clearly.

🎯 Goal: Create a struct to represent a digital asset, store multiple assets, and display their details.

📋 What You'll Learn

Create a struct called Asset with fields name (string), owner (string), and value (uint).

Create a list called assets to hold multiple Asset structs.

Add a configuration variable minValue to filter assets by their value.

Use a loop to select assets with value greater than or equal to minValue.

Print the details of the selected assets.

💡 Why This Matters

🌍 Real World

Structs help organize complex data in blockchain apps, like digital assets, transactions, or user profiles.

💼 Career

Understanding structs is key for blockchain developers to build clear, maintainable smart contracts and decentralized apps.

1

Define the Asset struct and create assets list

Define a struct called Asset with fields name (string), owner (string), and value (uint). Then create a list called assets with these exact entries: {"name": "ArtPiece", "owner": "Alice", "value": 100}, {"name": "CryptoKitty", "owner": "Bob", "value": 50}, and {"name": "RareCoin", "owner": "Charlie", "value": 200}.

Blockchain / Solidity

// Define struct Asset and create list assets with 3 entries
// Your code here

Need a hint?

Use struct keyword to define Asset. Create an array of Asset with the given entries.

2

Add a minimum value filter

Create a variable called minValue of type uint and set it to 100.

Blockchain / Solidity

struct Asset {
    string name;
    string owner;
    uint value;
}

Asset[] assets = [
    Asset("ArtPiece", "Alice", 100),
    Asset("CryptoKitty", "Bob", 50),
    Asset("RareCoin", "Charlie", 200)
];

// Create uint minValue and set to 100
// Your code here

Need a hint?

Use uint minValue = 100; to set the minimum value filter.

3

Select assets with value >= minValue

Create a new list called selectedAssets of type Asset[]. Use a for loop with variable i to go through assets. Inside the loop, use an if statement to check if assets[i].value is greater than or equal to minValue. If yes, add assets[i] to selectedAssets.

Blockchain / Solidity

struct Asset {
    string name;
    string owner;
    uint value;
}

Asset[] assets = [
    Asset("ArtPiece", "Alice", 100),
    Asset("CryptoKitty", "Bob", 50),
    Asset("RareCoin", "Charlie", 200)
];

uint minValue = 100;

// Create Asset[] selectedAssets and add assets with value >= minValue
// Your code here

Need a hint?

Use a for loop and if condition to filter assets. Use push to add to selectedAssets.

4

Print selected assets details

Use a for loop with variable j to go through selectedAssets. Inside the loop, print the asset's name, owner, and value in this exact format: Asset: [name], Owner: [owner], Value: [value].

Blockchain / Solidity

struct Asset {
    string name;
    string owner;
    uint value;
}

Asset[] assets = [
    Asset("ArtPiece", "Alice", 100),
    Asset("CryptoKitty", "Bob", 50),
    Asset("RareCoin", "Charlie", 200)
];

uint minValue = 100;

Asset[] selectedAssets;

for (uint i = 0; i = minValue) {
        selectedAssets.push(assets[i]);
    }
}

// Print details of selectedAssets
// Your code here

Need a hint?

Use a for loop and string concatenation to prepare each selected asset's details for output. Solidity does not support console.log; instead, return the strings or emit events.