Meu exemplo de conta corrente com if-else.

import java.util.Scanner;

public class ContaCorrente { public static void main(String[] args) { String name = "Marcelo Aires das Neves"; String numberType = "Current"; double balance = 1599.99; int options = 0; double newValue; double amountTransfer = 0;

    System.out.println("***************************");
    System.out.println("Client data: \n");

    System.out.println("Name: " + name);
    System.out.println("Account Type: " + numberType);
    System.out.println("Initial Balance: " + balance);
    System.out.println("***************************\n");

    String menu = """
            \nMenu Options
            1- Check the Balance
            2- Transfer Amount
            3- Enter the Amount
            4- Exit
            \nChoose the options:""";

    Scanner reading = new Scanner(System.in);
    while (options != 4) {
        System.out.print(menu);
        options = reading.nextInt();
        //4- Exit
        if (options == 4) {
            System.out.println("Exit the transactions Account.");
        }
        else if (options >= 5) {
            System.out.println("Selection the number options Menu between (1, 2, 3 and 4)");
        }
        //1- Check the Balance
        else if (options == 1) {
            balance = balance;
            System.out.println("The balance is " + balance);
        }
        //2- Transfer Amount
        else if (options == 2) {
            System.out.print("Insert the value to transfer: ");
            amountTransfer = reading.nextDouble();
            if (amountTransfer <= 0){
                System.out.println("You need to insert the value more than Zero.");
                balance += amountTransfer;
            }
            if (amountTransfer > balance){
                System.out.println("Isn't possible to transfer, You haven't money.");
                System.out.printf("Your balance is $%.2f. Insert the limite value or less.", balance);
                System.out.print("\nInsert the transfer value to transfer: ");
                amountTransfer = reading.nextDouble();
                balance -= amountTransfer;
                System.out.println("The balance is " + balance);
            }else if(amountTransfer <= balance) {
                balance -= amountTransfer;
                System.out.println("The balance is " + balance);
            }
        }
        //3- Enter the Amount
        else if (options == 3) {
            System.out.print("Insert the value to account: ");
            newValue = reading.nextDouble();
            if (newValue <= 0){
                System.out.println("You need to insert the value more than Zero.");
                newValue = 0;
            }else {
                //System.out.println("You need to insert the value more than Zero.");
                balance += newValue;
                System.out.println("The balance is " + balance);
            }
        }
   }
}

}