I cant get the java file to give me error -

i created main java program works bank giving user balance, withdrawls , transfer money.

import java.util.scanner;  public class lab12 {     public static void main(string[] args)     {         //creating 2 bankaccounts         bankaccount b1 = new bankaccount(1000, "asu_account_110");         bankaccount b2 = new bankaccount(500, "asu_account_100");         double amount;         scanner scan  = new scanner(system.in);          //account deposit         system.out.println("please enter amount deposit asu_account_110 account");         amount = scan.nextdouble();         if(!b1.deposit(amount))             system.out.println("error depositing amount in account. please enter positive value.");         else             system.out.println("successfully deposited $"+amount+". current balance "+b1.getbalance() );          //account withdrawal         system.out.println("please enter amount withdraw asu_account_110");         amount = scan.nextdouble();         if(!b1.withdraw(amount))             system.out.println("error withdrawing amount. either overdrawing or have entered negative value");         else             system.out.println("successfully withdrew $"+amount+". current balance "+b1.getbalance());          //account transfer         system.out.println("please enter amount transfer asu_account_110 asu_account_100");         amount = scan.nextdouble();         if(!b1.transfer(amount, b2))         {             system.out.println("error transfering amount. either overdrawing or have entered negative value");         }         else         {             system.out.println("successfully transferred $"+amount+".\nthe current balance in asu_account_110 "+b1.getbalance());             system.out.println("the current balance in asu_account_100 "+b2.getbalance());         }          //account display         system.out.println("\nthe details of 2 accounts are:");         system.out.println("------------------------------------------");         display(b1);         system.out.println("------------------------------------------");         display(b2);     }      public static void display(bankaccount b)     {         system.out.println("the account number "+b.getaccountnumber());         system.out.println("the balance "+b.getbalance());     } } 

i created second class has methods , gets , calls balances

public class bankaccount {      private string accountnumber;     private double balance;      public bankaccount(double balance, string accountnumber)      {         this.balance = balance;         this.accountnumber = accountnumber;     }      public boolean deposit(double amount)      {         return true;     }      public double getbalance()      {         return balance;     }      public boolean withdraw(double amount)      {         return true;     }      public boolean transfer(double amount, bankaccount b2)      {         return true;     }      public string getaccountnumber()      {         return accountnumber;     } } 

the problem when enter negative amount deposit, withdrawal, transfer, not getting error put in main class

any thoughts?

you not check if number negative anywhere in bankaccount.deposit(double). need check if code negative this:

public boolean deposit(double amount)  {     if(amount<0)     {         return false;     }else{         return true;     } }