Why won't the if's detect the string values in my boolean opperator? [duplicate]

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• How do I compare strings in Java? 23 answers

So I'm trying to write a GPA calculator that allows the user to input the grades and tell it to stop when they type "Done". When I test it however, the code doesn't initialize inside the if statement when all conditions are met. Even when checking to see that it each string matches in the debugger. Please tell me what I'm doing wrong!

note this is a case sensitive version of my code, however it did the same thing when I made it without case sensitivity

Scanner grade = new Scanner(System.in);
    getGrades:
    while(true)
    {

        grades = grade.next();
        if(grades == "A")
        {
            letterGrade = a;
            numberOfGrades++;
        }
        else if(grades == "A-")
        {
            letterGrade = aMinus;
            numberOfGrades++;
        }
        else if(grades == "B+")
        {
            letterGrade = bPlus;
            numberOfGrades++;
        }
        else if(grades == "B")
        {
            letterGrade = b;
            numberOfGrades++;
        }
        else if(grades == "B-")
        {
            letterGrade = bMinus;
            numberOfGrades++;
        }
        else if(grades == "C+")
        {
            letterGrade = cPlus;
            numberOfGrades++;
        }
        else if(grades == "C")
        {
            letterGrade = c;
            numberOfGrades++;
        }
        else if(grades == "C-")
        {
            letterGrade = cMinus;
            numberOfGrades++;
        }
        else if(grades == "D+")
        {
            letterGrade = dPlus;
            numberOfGrades++;
        }
        else if(grades == "D")
        {
            letterGrade = d;
            numberOfGrades++;
        }
        else if(grades == "D-")
        {
            letterGrade = dMinus;
            numberOfGrades++;
        }
        else if(grades == "F")
        {
            letterGrade = f;
            numberOfGrades++;
        } 
        else if(grades == "Done")
        {
            break getGrades;
        }
        totalGrade = totalGrade + letterGrade;
    }
    return totalGrade;