diff --git a/StringsAndTings.js b/StringsAndTings.js
index 4fdca47..b1e134e 100644
--- a/StringsAndTings.js
+++ b/StringsAndTings.js
@@ -2,28 +2,62 @@ class StringsAndTings {
     
     // @return string with identical content, and the first character capitalized
     camelCase(str){
-        return null;
+        let strSplit= str.split(" ");
+        for(let i = 0; i < strSplit.length; i++){
+            let word = strSplit[i];
+            strSplit[i] = word[0].toUpperCase() + word.substring(1);
+        }
+        return strSplit.join(" ");
     }
 
     //@return string with identical contents, with each word individually in reverse order
     reverseString(str){
-        return null;
+        let revStr = "";
+        for( let i = str.length -1; i >= 0; i--) {
+            revStr += str[i];
+        }
+        return revStr;
+    }
+
+    //@return string with identical contents, with each word individually in reverse order
+    reverseWords(str){
+        let revWords = str.split(" ");
+        for( let i = revWords.length -1; i >= 0; i--) {
+            revWords += str[i];
+        }
+        return str.split("").reverse().join("");
     }
 
     // @return string with identical contents, in reverse order, with first character capitalized
     reverseThenCamelCase(str){
-        return null;
+        let revCamel = this.reverseString(str);
+        return this.camelCase(revCamel);
     }
 
     // @return string with identical contents excluding first and last character
     removeFirstAndLastCharacter(str){
-        return null;
+        let result = str.substring(1, str.length-1);
+        return result;
     }
 
     // @return string with identical characters, each with opposite casing
     invertCasing(str){
-        return null;
+        let invert = "";
+        let i = 0;
+        while (i < str.length) {
+            let m = str.charAt(i);
+                if (m === m.toUpperCase()) {
+                    m = m.toLowerCase();
+                } else {
+                    m = m.toUpperCase();
+                } 
+                i += 1
+                invert += m;
+            }
+            return invert;
     }
+
+    
 }
 
 module.exports = StringsAndTings;
\ No newline at end of file
diff --git a/StringsAndTings.test.js b/StringsAndTings.test.js
index 689b63d..b5a06da 100644
--- a/StringsAndTings.test.js
+++ b/StringsAndTings.test.js
@@ -8,7 +8,7 @@ test("camelCaseTest", () => {
     let input = "she sells sea shells";
     let expected = "She Sells Sea Shells";
 
-    let actual = stringsAndTings.camelCase(15);
+    let actual = stringsAndTings.camelCase(input);
 
     expect(actual).toEqual(expected);
 });
@@ -19,7 +19,7 @@ test("reverseTest", () => {
     let input = "she sells sea shells";
     let expected = "sllehs aes slles ehs";
 
-    let actual = stringsAndTings.camelCase(15);
+    let actual = stringsAndTings.reverseString(input);
 
     expect(actual).toEqual(expected);
 });
@@ -30,7 +30,7 @@ test("reverseWordsTest", () => {
     let input = "she sells sea shells";
     let expected = "ehs slles aes sllehs";
 
-    let actual = stringsAndTings.camelCase(15);
+    let actual = stringsAndTings.reverseWords(input);
 
     expect(actual).toEqual(expected);
 });
@@ -41,7 +41,7 @@ test("reverseThenCamelCaseTest", () => {
     let input = "she sells sea shells";
     let expected = "Sllehs Aes Slles Ehs";
 
-    let actual = stringsAndTings.camelCase(15);
+    let actual = stringsAndTings.reverseThenCamelCase(input);
 
     expect(actual).toEqual(expected);
 });
@@ -52,19 +52,18 @@ test("removeFirstAndLastCharacterTest", () => {
     let input = "she sells sea shells";
     let expected = "he sells sea shell";
 
-    let actual = stringsAndTings.camelCase(15);
+    let actual = stringsAndTings.removeFirstAndLastCharacter(input);
 
     expect(actual).toEqual(expected);
 });
 
-
 test("invertCasingTest1", () => {
 
     let stringsAndTings = new StringsAndTings();
     let input = "shE sells SEA sHeLlS";
     let expected = "SHe SELLS sea ShElLs";
 
-    let actual = stringsAndTings.camelCase(15);
+    let actual = stringsAndTings.invertCasing(input);
 
     expect(actual).toEqual(expected);
 });
diff --git a/package.json b/package.json
index 5ae2c26..38f3819 100644
--- a/package.json
+++ b/package.json
@@ -9,6 +9,6 @@
   "author": "Tariq Hook",
   "license": "ISC",
   "devDependencies": {
-    "jest": "^26.4.2"
+    "jest": "^26.6.3"
   }
 }