Does JOptionPane.showInputDialog() return a different String

Question

Is the String returned by JOptionPane.showInputDialog() different from a regular String? When I try to compare it with "2", it returns false and go to the else block.

        // Prompt user for the month
        String monthString = JOptionPane.showInputDialog(
                "Enter which month are you looking for: "); 

        // SMALL Months, ie: 2, 4, 6, 9, 11
        else {
            // Special case on February
            if (monthString == "2" && isLeap) 
                            result += "29 days!";
            else if (monthString == "2")
                result += "28 days!";
            // Everytime my code to go to this block instead
            else
                result += "30 days!";
        }

Only work if I parse month to Int and then compare it with literal 2. Why do my original version does not work?

int month = Integer.parseInt(monthString);
if (month == 2 && isLeap) ...

Answer 1

Use equals to compare string and not ==

Change this:

monthString == "2"

to

"2".equals(monthString) 

in your if blocks

Equals compare the string contents while == compares the object equality. Read more from the related post here:

Java String.equals versus ==

Also note the reverse comparision "2" against the monthStirng. This will prevent null pointer exception in case monthString is null.