completed the JavaStringCheese program

StringParser.java

  */
 public class StringParser
 {
+    private static String s1;
     /**
      * Takes a String and returns that String with all characters uppercased.
      * E.G. cat would become CAT. dOnUt would become DONUT.
      */
     public static String upperCaseString(String s)
     {
-        return null;
+        return s.toUpperCase();
     }
 
     /**
      * @return String
      */
     public static String lowerCaseString(String s) {
-        return null;
+        return s.toLowerCase();
     }
 
     /**
      * @return String
      */
     public static Character getFirstCharacter(String s) {
-        return null;
+        return s.charAt(0);
     }
 
     /**
      * @return String
      */
     public static Character getNthCharacter(String s, Integer n) {
-        return null;
+        return s.charAt(n);
     }
 
     /**
      * @return String
      */
     public static String upperCaseFirstCharacter(String s) {
-        return null;
+        s1 = s.substring(0,1).toUpperCase() + s.substring(1);
+        return s1;
     }
 
     /**
      * @return String
      */
     public static String camelCaseString(String s) {
+        //String s2 = "";
+        s1 = s.toLowerCase();
+        //s1 = s1.subString(0,1) + s1.subString(1);
+        //StringBuffer bf = new StringBuffer(s1);
+        for(int i=0;i<s1.length();i++)
+        {
+            if(s1.charAt(i) == ' '){
+                s=s1.substring(0,1).toUpperCase()+s1.substring(1,i);
+                s1=s1.substring(i+1,i+2).toUpperCase()+s1.substring(i+2);
+                return s+s1;
+            }
+            else{
+            s=s1.substring(0,1).toUpperCase()+s1.substring(1);
+        }
+        }
+        
         return null;
     }
 
      * @return String
      */
     public static String snakeCaseString(String s) {
-        return null;
+        
+        StringBuffer bf = new StringBuffer(s.toLowerCase());
+        for(int i=0;i<bf.length();i++)
+        {
+            if(bf.charAt(i) == ' ')
+            {
+                bf.insert(i,"_");
+                bf.deleteCharAt(i+1);
+                s= bf.toString();
+                return s;
+            }
+        }    
+        return s;
     }
 
     /**
      * @return String
      */
     public static Integer getLength(String s) {
-        return null;
+        return s.length();
     }
 
     /**
      * @return String
      */
     public static Boolean isEqual(String s1, String s2) {
-        return null;
+        return s1.equals(s2);
     }
 
     /**
      * @return String
      */
     public static Boolean isEqualIgnoreCase(String s1, String s2) {
-        return null;
+        return s1.equalsIgnoreCase(s2);
     }
 }

package.bluej

 #BlueJ package file
-#Wed Oct 17 09:06:47 EDT 2018
+editor.fx.0.height=0
+editor.fx.0.width=0
+editor.fx.0.x=0
+editor.fx.0.y=0
+objectbench.height=99
+objectbench.width=1256
+package.divider.horizontal=0.6
+package.divider.vertical=0.8379204892966361
+package.editor.height=541
+package.editor.width=1154
+package.editor.x=0
+package.editor.y=23
+package.frame.height=712
+package.frame.width=1280
+package.numDependencies=0
+package.numTargets=2
+package.showExtends=true
+package.showUses=true
 project.charset=UTF-8
+readme.height=58
+readme.name=@README
+readme.width=47
+readme.x=10
+readme.y=10
+target1.height=50
+target1.name=StringParser
+target1.showInterface=false
+target1.type=ClassTarget
+target1.width=100
+target1.x=140
+target1.y=10
+target2.height=50
+target2.name=StringParserTest
+target2.showInterface=false
+target2.type=UnitTestTargetJunit4
+target2.width=130
+target2.x=70
+target2.y=70