my java string cheese

StringParser.java

+package JavaStringCheese;
+
 
 /**
  * An introduction to Strings and String methods.
      */
     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;
+        String s1= s.substring(0,1);
+        return s1.toUpperCase() + s.substring(1);
     }
 
     /**
      * @return String
      */
     public static String camelCaseString(String s) {
-        return null;
+        s=s.toLowerCase(); //first convert string to ,lower case
+        String[] s1=s.split(" "); // now convert string to an array
+        String result="";
+        for(int i=0; i<s1.length; i++)
+        {
+           result= result+ s1[i].toUpperCase().charAt(0) +s1[i].substring(1);
+           // sysntax to remember-> s.toUpperCase.charAt(0) +s.substring -> for converting first char of string to capital and then joining
+        }
+        return result;
     }
 
     /**
      * @return String
      */
     public static String snakeCaseString(String s) {
-        return null;
+        String s1= "";
+         //s= s.split("");
+        for(int i=0; i< s.length() ;i++)
+        {
+            if (s.charAt(i) == ' ')
+            {
+                s1=s1 +"_";
+            }
+            else {s1= s1 + s.toLowerCase().charAt(i);}
+        }
+        
+        return s1.toLowerCase();
     }
 
     /**
      * @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);
     }
 }

StringParserTest.java

+package JavaStringCheese;
+
 import org.junit.Test;
 
 import static org.junit.Assert.*;

package.bluej

 dependency1.from=StringParserTest
 dependency1.to=StringParser
 dependency1.type=UsesDependency
-editor.fx.0.height=722
-editor.fx.0.width=800
-editor.fx.0.x=455
-editor.fx.0.y=51
 objectbench.height=164
-objectbench.width=776
+objectbench.width=461
 package.divider.horizontal=0.6
 package.divider.vertical=0.6845018450184502
 package.editor.height=364
 package.numTargets=2
 package.showExtends=true
 package.showUses=true
-project.charset=UTF-8
 readme.height=58
 readme.name=@README
 readme.width=47