java variable not initialized
<p>hi i have issue with the following program as it gives me an error says that <code>variable gradePoints might not have been initialized</code>, what am i missing here..? also how can i improve the code so that it accept letters a+ as A+ and any other input throw an error? Thanks!!</p>

<pre><code>   import java.lang.*;
import java.io.*;
import java.util.*;
import java.util.Scanner;

  public class Program
 {
 static final Map&lt;String, Double&gt; gradeToPointMap =
        new LinkedHashMap&lt;String, Double&gt;() {{
            put("A+", 4.0);
            put("A", 4.0);
            put("A-", 3.7);
            put("B+", 3.3);
            put("B", 3.0);
            put("B-", 2.7);
            put("C+", 2.3);
            put("C", 2.0);
            put("C-", 1.7);
            put("F", 0.0);
        }};

public static void main(String[] args) {
    Scanner keyboard = new Scanner(System.in);

    System.out.println("Enter A Letter Grade: ");
    String letterGrade = keyboard.next();

    getGradePoint(letterGrade);


}
     public double getGradePoint(String letterGrade)
     {
         Double gradePoints = gradeToPointMap.get(letterGrade.toUpperCase());
    if (gradePoints == null)
        System.out.println("Unknown letter grade " + letterGrade);
    else
        System.out.println("Your grade point(GPA) is " + gradePoints);
     }

 }
</code></pre>
