What is the correct way to declare a boolean variable in Java?

Question

I have just started learning Java. In the online course I am following, I am asked to try the following code:

String email1 = "[email protected]";
String email2 = "[email protected]";
Boolean isMatch = false;

isMatch = email1.equals (email2);

if (isMatch == true){
    System.out.println("Emails match");
}
else{
    System.out.println("Emails don't match");
}

I don't understand why I'm asked to declare isMatch as false when on the next line i am comparing the email addresses and assigning the value to isMatch.
I've tried the following code which seems to work just the same:

String email1 = "[email protected]";
String email2 = "[email protected]";
Boolean isMatch;

isMatch = email1.equals (email2);

if (isMatch == true){
    System.out.println("Emails match");
}
else{
    System.out.println("Emails don't match");
}

On the course it doesn't explain why I'm declaring isMatch as false first. Is there a reason why I must declare isMatch as false before comparing the email addresses?

Answer 1

Not only there is no need to declare it as false first, I would add few other improvements:

• use boolean instead of Boolean (which can also be null for no reason)

• assign during declaration:

  boolean isMatch = email1.equals(email2);
  

• ...and use final keyword if you can:

  final boolean isMatch = email1.equals(email2);
  

Last but not least:

if (isMatch == true)

can be expressed as:

if (isMatch)

which renders the isMatch flag not that useful, inlining it might not hurt readability. I suggest looking for some better courses/tutorials out there...