Struct - Custom Data Structures

The Struct type allows you to create custom data structures by grouping related data fields together. It's useful for organizing complex data and creating reusable data models.

Syntax

class StructName {
  field1: Type1;
  field2: Type2;
  field3: Type3;
}

Overview

Struct provides:

• Custom data grouping
• Related field organization
• Reusable data models
• Type-safe field access
• Memory-efficient storage

Basic Usage

Simple Struct

class UserInfo {
  id: U256;
  name: String;
  isActive: Boolean;
}

@Contract
export class UserManager {
  static currentUser: UserInfo;

  @External
  static createUser(id: U256, name: String): void {
    const user = new UserInfo();
    user.id = id;
    user.name = name;
    user.isActive = true;
    
    currentUser = user;
  }

  @View
  static getUser(): UserInfo {
    return UserManager.currentUser;
  }
}

Struct with Multiple Fields

class TokenInfo {
  amount: U256;
  recipient: Address;
  timestamp: U256;
}

@Contract
export class TokenTracker {
  static lastTransfer: TokenInfo;

  @External
  static recordTransfer(amount: U256, recipient: Address, timestamp: U256): void {
    const transfer = StructFactory.create<TokenInfo>([
      amount,
      recipient,
      timestamp,
    ]);
    
    lastTransfer = transfer;
  }

  @View
  static getLastTransfer(): TokenInfo {
    return TokenTracker.lastTransfer;
  }
}

Common Patterns

Configuration Data

class Config {
  maxSupply: U256;
  ownerAddress: Address;
  isPaused: Boolean;
}

@Contract
export class ConfigContract {
  static settings: Config;

  @External
  static updateConfig(maxSupply: U256, owner: Address, paused: Boolean): void {
    const config = new Config();
    config.maxSupply = maxSupply;
    config.ownerAddress = owner;
    config.isPaused = paused;
    
    ConfigContract.settings = config;
  }
}

User Profile

class Profile {
  username: String;
  balance: U256;
  joinDate: U256;
}

@Contract
export class ProfileManager {
  static userProfile: Profile;

  @External
  static createProfile(username: String, balance: U256, joinDate: U256): void {
    const profile = StructFactory.create<Profile>([
      username,
      balance,
      joinDate,
    ]);
    userProfile = profile;
  }

  @View
  static getProfile(): Profile {
    return userProfile;
  }
}

Game Data

class PlayerStats {
  level: U256;
  score: U256;
  lives: U256;
}

@Contract
export class GameContract {
  static player: PlayerStats;

  @External
  static updateStats(level: U256, score: U256, lives: U256): void {
    const stats = StructFactory.create<PlayerStats>([
      level,
      score,
      lives
    ])
    player = stats;
  }

  @View
  static getStats(): PlayerStats {
    return player;
  }
}

Supported Field Types

class AllTypes {
  numberField: U256;        // ✅ Numbers
  signedField: I256;        // ✅ Signed numbers
  addressField: Address;    // ✅ Addresses
  textField: String;        // ✅ Text
  flagField: Boolean;       // ✅ True/false
}

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🏗️ More Data Structures

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