的System.out.println（）;和System.err.println（）;可互换印刷

Question

This code is part of a program.

System.out.print("Enter your deposit amount: ");
double deposit = scanner.nextDouble();
bankObj.deposit(deposit); //this method will print a syserr if the number entered is negative
if (deposit > 0) {
    System.out.println("Thank you for depositing the amount of "+deposit+" to account number "+bankObj.accountNum+".");
}
    System.out.println("Program exiting.");

Output:

Enter your deposit amount: -2
//sometimes it will print.
Program exiting.
Account.deposit(...): cannot deposit negative amount. //This is from the deposit method
//or
Account.deposit(...): cannot deposit negative amount. //This is from the deposit method
Program exiting.

Why is this happening? I tried putting it outside loops and statements (those might be the problem) but the behavior didn't change. I'm using Eclipse.

Answer 1

Those are two different output streams, the order in which they are invoked is not the only thing that matters. They might flush their contents towards the console at a different time.

Edit: after a bit more digging this answer indicates that it might be an (unresolved) eclipse bug as well. It's been open for 10 years, don't get your hopes up on a fix anytime soon.