Complted part 1

basicMath/MathUtilities.js

@@ -2,19 +2,19 @@ class MathUtilities {
 
 
     add(baseValue, valueToAdd){
-        return -1;
+        return baseValue + valueToAdd;
     }
 
     subtract(baseValue, valueToAdd){
-        return -1;
+        return baseValue - valueToAdd;
     }
 
     divide(baseValue, valueToAdd){
-        return -1;
+        return baseValue / valueToAdd;
     }
 
     multiply(baseValue, valueToAdd){
-        return -1;
+        return baseValue * valueToAdd;
     }
 }
 

basicMath/MathUtilities.test.js

@@ -74,7 +74,7 @@ test("Test 2 Integer Division", () => {
     let addedValue = 1;
 
     // When
-    let expected = 127;
+    let expected = 2;
     let actual = math.divide(baseValue, addedValue);
     //Then
     expect(actual).toEqual(expected);

strangerStrings/StrangerStrings.js

@@ -1,35 +1,74 @@
 class StrangerStrings {
 
     getHelloWorld(){
-        return null;
+        let helloWorld = "Hello World";
+        return helloWorld
     }
 
     concatenation(firstSegment, secondSegment){
-        return null;
+        return firstSegment + secondSegment;
     }
 
     getPrefix(input){
-        return null;
+        let firstLetter = input[0]
+        let secondLetter = input[1]
+        let thirdLetter = input[2]
+        return firstLetter + secondLetter + thirdLetter;
     }
 
     getSuffix(input){
-        return null;
+        // get the 3rd to last letter.
+        let thirdToLastLetter = input[input.length - 3];
+        // get the 2nd letter.
+        let secondToLastLetter = input[input.length - 2];
+        // get the last letter.
+        let lastLetter = input[input.length - 1];
+        return thirdToLastLetter + secondToLastLetter + lastLetter;
+
     }
 
     getMiddleCharacter(input){
-        return null;
+        //get input length
+        let inputLength = input.length;
+        //divide length by two to cut in half. Math.floor to round down since string is an odd number.
+        let middle = Math.floor(inputLength / 2);
+        //return middle of input value.
+        if (inputLength % 2 == 0){
+            // if even 
+            return input[middle -1] + input[middle];
+        } else {
+            return input[middle];
+        }
+
     }
 
-    getFirstWord(input){
-        return null;
+    getFirstWord(inputValue){
+        // split up the string using .split(). Turns a string into an array.
+        let x = inputValue.split(" ");
+        // get the first index of the array.
+        let firstWord = x[0];
+        // return the first word.
+        return firstWord;
     }
 
-    getSecondWord(spaceDelimnatedInput){
-        return null;
+    getSecondWord(inputValue){
+        // turn input value into a string using .split()
+        let x = inputValue.split(" ");
+        // get the second index of the array.
+        let secondWord = x[1];
+        // return the second word.
+        return secondWord;
     }
 
-    reverse(input){
-        return null;
+    reverse(inputValue){
+        // turn input value into a string using .split()
+        let x = inputValue.split("");
+        // reverse the array using .reverse()
+        let strToArray = x.reverse();
+        // turn the array back to a string with .join()
+        let backwardArray = strToArray.join(""); 
+        // return joined reversed string.
+        return backwardArray;
     }
 }
 

strangerStrings/StrangerStrings.test.js

@@ -58,10 +58,10 @@ test("return the last 3 characters of `input`", () => {
 });
 
 
-test("return the middle character of `inputValue`", () => {
+test("return the middle character of `input`", () => {
     // Given
     let strangerStrings = new StrangerStrings();
-    let inputValue = 'MethodMan';
+    let input = 'MethodMan';
 
     let expected = "o";