troubleshot display mode methods, all working now

MathMethods.java

@@ -9,7 +9,8 @@ import java.lang.*;
 public class MathMethods
 
 {
-
+    private static int displayModeCounter=4;
+    
     public static Double add(double n1, double n2){
         return (n1 + n2);
     }
@@ -83,15 +84,15 @@ public class MathMethods
 
     public static String switchDisplayMode(String mode){
         Calculator display = new Calculator();
-        
+
         String answer = "";
         switch (mode) {
             case "binary":
-            answer = "0b" + Integer.toBinaryString((int)display.memory);
+            answer = "0b " + Integer.toBinaryString((int)display.memory);
             break;
 
             case "octal":
-            answer = "octal" + Integer.toOctalString((int)display.memory);
+            answer = "0 " + Integer.toOctalString((int)display.memory);
             break;
 
             case "decimal":
@@ -99,31 +100,31 @@ public class MathMethods
             break;
 
             case "hexadecimal":
-            answer = Double.toHexString(display.memory);
+            answer = "0x " + Integer.toHexString((int)display.memory);
             break;
 
         }
         return answer;
     }
 
-    public static String switchDisplayMode(){
-        int i = 4;
+    public String switchDisplayMode(){
+
         String answer = "";
 
-        if (i%4 == 0){ 
+        if (displayModeCounter%4 == 0){ 
             answer = switchDisplayMode("binary");
-            i++;
+            displayModeCounter++;
         } 
-        else if (i%4 == 1){
+        else if (displayModeCounter%4 == 1){
             answer = switchDisplayMode("octal");
-            i++;
+            displayModeCounter++;
         } 
-        else if (i%4 == 2) {
-            answer = switchDisplayMode("hecadecimal");
-            i++;
+        else if (displayModeCounter%4 == 2) {
+            answer = switchDisplayMode("hexadecimal");
+            displayModeCounter++;
         } else {
             answer = switchDisplayMode("decimal");
-            i++;
+            displayModeCounter++;
         }
         return answer;
     }
@@ -135,4 +136,3 @@ public class MathMethods
 
 }
 
-

MathMethodsTest.java

@@ -77,6 +77,14 @@ public class MathMethodsTest
     }
 
     
+
+    // @Test
+    // public void testOctalDisplay()
+    // {
+        // MathMethods mathMethods1 = new MathMethods();
+        // mathMethods1.memory = 20;
+        // assertEquals(0 24, MathMethods.switchDisplayMode("octal"));
+    // }
 }
 
 
@@ -85,3 +93,4 @@ public class MathMethodsTest
 
 
 
+