Improved Step 21-30: OOP Design + Improved Instructions in READMEs

step21_web3_node_getbalance/.gitignore

@@ -1,2 +1,5 @@
+# Node packages
 node_modules
-*.js
+
+# Build files created by TypeScript Compiler
+*.js

step21_web3_node_getbalance/EthereumAccount.ts

@@ -1,23 +1,37 @@
-import Web3 from 'web3';
+import Web3 from "web3";
+
+// Create a new project on Infura and replace PROJECT_ID
+// in the following line with your Infura project id.
+const RPC_ENDPOINT = "https://mainnet.infura.io/v3/PROJECT_ID";
 
 //https://www.typescriptlang.org/docs/handbook/2/classes.html
 export class EthereumAccount {
+  private web3: Web3;
+  private address: string;
 
-    private web3: Web3;
-    private address: string;
-
-    // Got an Default Account Address from Etherscan: https://etherscan.io/accounts
-    public constructor(address: string = "0xDeE6238780f98c0ca2c2C28453149bEA49a3Abc9") {
-        this.address = address;
-        this.web3 = new Web3("https://mainnet.infura.io/v3/b56ef5c27bca4880844888e6a12a16ef");
-
-    }
+  /**
+   * Instantiate an Ethereum Account object.
+   * @param address Public address of the account on Ethereum Network.
+   */
+  public constructor(address: string) {
+    this.address = address;
+    this.web3 = new Web3(RPC_ENDPOINT);
+  }
 
-    public getAddress(): string {
-      return this.address;
-    }
+  /**
+   * Get the public address of the Ethereum account.
+   * @returns public address of the Ethereum account.
+   */
+  public getAddress(): string {
+    return this.address;
+  }
 
-    public async getBalance() {
-      return await this.web3.eth.getBalance(this.address);
-    }
-  }
+  /**
+   * Get the number of Ethers in the Ethereum account.
+   * @returns Ethers (ETH) in the Ethereum account.
+   */
+  public async getBalance() {
+    const balance = await this.web3.eth.getBalance(this.address);
+    return this.web3.utils.fromWei(balance, "ether");
+  }
+}

step21_web3_node_getbalance/index.ts

@@ -1,8 +1,18 @@
-import { EthereumAccount } from './EthereumAccount';
+import { EthereumAccount } from "./EthereumAccount";
 
-const account : EthereumAccount = new EthereumAccount();
-
-account.getBalance().then(response => console.log(response));
+const numberFormator = new Intl.NumberFormat("us-EN", {
+  style: "currency",
+  currency: "ETH",
+});
 
+// Get any Account Address from Etherscan: https://etherscan.io/accounts
+const accountAddress = "0x53d284357ec70ce289d6d64134dfac8e511c8a3d";
 
+(async () => {
+  // Instantiate an Ethereum account instance.
+  const account = new EthereumAccount(accountAddress);
 
+  console.log("Account Address:", account.getAddress());
+  const balance = await account.getBalance();
+  console.log("Account Balance:", numberFormator.format(+balance));
+})();