more test

src/main/java/rocks/zipcode/quiz5/fundamentals/StringUtils.java

@@ -1,5 +1,6 @@
 package rocks.zipcode.quiz5.fundamentals;
 
+import java.util.Arrays;
 import java.util.HashSet;
 import java.util.Set;
 
@@ -19,44 +20,91 @@ public class StringUtils {
     }
 
     public static String capitalizeMiddleCharacter(String str) {
+       int positon;
 
-        return null;
+       if (str.length() % 2==0){
+           positon = str.length()/ 2 -1;
+
+       }else {
+           positon = str.length()/2;
+       }
+
+
+
+        return str.substring(0,positon) + str.toUpperCase().charAt(positon)+ str.substring(positon,str.length() - 1);
     }
 
     public static String lowerCaseMiddleCharacter(String str) {
-        return null;
+
+        int middle;
+
+        if (str.length() % 2==0){
+            middle = str.length()/ 2 -1;
+
+
+        }else {
+            middle = str.length()/2;
+        }
+return str.substring(0,middle) + str.toLowerCase().charAt(middle)+ str.substring(middle,str.length()-1);
     }
 
     public static Boolean isIsogram(String str) {
-        return null;
+        str.toLowerCase();
+        char arr [] = str.toCharArray();
+        Arrays.sort(arr);
+
+        for (int i = 0; i <arr.length -1 ; i++) {
+            if (arr[i] == arr[i+1]) {
+
+                return true;
+
+            }
+
+        }
+        return false;
     }
 
     public static Boolean hasDuplicateConsecutiveCharacters(String str) {
-        String [] arr = str.split("");
+        char [] arr = str.toCharArray();
+
         for (int i = 0; i <arr.length-1; i++) {
-            for (int j = i+ 1; j <arr.length; j++) {
-                if (arr[i] == arr[j]){
-                    return true;
-                }
+             if ( arr[i]== arr[i + 1]){
+                 return true;
+             }
 
             }
 
-        }
-
 
 
         return false;
     }
 
     public static String removeConsecutiveDuplicateCharacters(String str) {
+        
 
 
 
-
-        return null;
+        return  ;
     }
 
     public static String invertCasing(String str) {
-        return null;
+        char [] ch = str.toCharArray();
+
+        for (int i = 0; i <ch.length ; i++) {
+
+            char c = ch [i];
+            if (Character.isUpperCase(c)){
+
+                ch [i] = Character.toLowerCase(c);
+
+            } else if (Character.isLowerCase(c)){
+
+                ch [i]= Character.toUpperCase(c);
+
+            }
+
+        }
+        return new String(ch);
+
     }
 }