Why don't strings compare as equal? [duplicate]

Question

Possible Duplicate:
String is not equal to string?

I'm new to java and I can't figure out what's wrong with this code block. I know the array isn't null I'm testing it elsewhere. Maybe there is a syntax problem I'm used to program in c#.

     Scanner input = new Scanner(System.in);
     System.out.println("Enter ID :");
     String employeeId = input.nextLine();
     int index =  -1;
     for(int i = 0 ; i < employeeCounter ; i++)
     {
         if(employeeId == employeeNumber[i])
         {
           index = i;
         }
     }

     if(index == -1)
     {
         System.out.println("Invalid");
         return;
     }

I always get to the 'Invalid' part. Any idea why ? Thanks in advance

---

employeeNumber[0] is "12345" employeeId is "12345" but I can,t get into the first if statement although employeeId IS equal to employeeNumber[0].

Answer 1

Don't compare strings with ==.

Use

if (string1.equals("other")) {
    // they match
}

Answer 2

Compare strings like that

if(employeeId.equals(employeeNumber[i]) {

}

Answer 3

As others have pointed - full code will be helpful, but my guess would be this line of the code:

if(employeeId == employeeNumber[i])

You don't compare 2 strings by using ==. Use equals() or equalsIgnoreCase() instead. == only checks for object equality i.e. are employeeId and employeeNumber referencing to the same object in memory. So, for objects always use the equals() method..for Strings you can also use equalsIgnoreCase() for a case insensitive match. == should be used on primitive types like int, long etc.