CodeYourFuture · AnthonyMogotlane · Jul 10, 2022 · Jul 10, 2022 · Jul 11, 2022 · Jul 11, 2022
diff --git a/1-exercises/A-undefined/exercise.js b/1-exercises/A-undefined/exercise.js
@@ -11,15 +11,15 @@
 
 // Example 1
 let a;
-console.log(a);
+console.log(a); // Variable a hasn't been assigned a value.
 
 
 // Example 2
 function sayHello() {
     let message = "Hello";
 }
 
-let hello = sayHello();
+let hello = sayHello(); // Function sayHello is not returning anything, so hello variable is assigned to nothing, hence we get undefined.
 console.log(hello);
 
 
@@ -28,9 +28,9 @@ function sayHelloToUser(user) {
     console.log(`Hello ${user}`);
 }
 
-sayHelloToUser();
+sayHelloToUser();// The function is missing argument, and is not defined what it will be returning.
 
 
 // Example 4
 let arr = [1,2,3];
-console.log(arr[3]);
+console.log(arr[3]);// The index value is out of range, since the length of arr is 3 and the last element index is 2.
diff --git a/1-exercises/B-while-loop/exercise.js b/1-exercises/B-while-loop/exercise.js
@@ -6,9 +6,15 @@
 */
 
 function evenNumbers(n) {
-    // TODO
+    let res = [];
+    let num = 0;
+    while(res.length < n) {
+        res.push(num);
+        num += 2;
+    }
+    return res.join(",");
 }
 
 evenNumbers(3); // should output 0,2,4
 evenNumbers(0); // should output nothing
-evenNumbers(10); // should output 0,2,4,6,8,10,12,14,16,18
+evenNumbers(10); // should output 0,2,4,6,8,10,12,14,16,18
diff --git a/1-exercises/C-while-loop-with-array/exercise.js b/1-exercises/C-while-loop-with-array/exercise.js
@@ -17,7 +17,11 @@ const BIRTHDAYS = [
 ];
 
 function findFirstJulyBDay(birthdays) {
-    // TODO
+    let i = 0;
+    while(i < birthdays.length) {
+        if(birthdays[i].includes("July")) return birthdays[i];
+        i++;
+    }
 }
 
 console.log(findFirstJulyBDay(BIRTHDAYS)); // should output "July 11th"
diff --git a/1-exercises/D-do-while/exercise.js b/1-exercises/D-do-while/exercise.js
@@ -7,7 +7,13 @@
 */
 
 function evenNumbersSum(n) {
-    // TODO
+    let sum = [];
+    let num = 0;
+    do {
+        sum.push(num)
+        num += 2;
+    } while (sum.length < n)
+    return sum.reduce((tot, num) => tot + num);
 }
 
 console.log(evenNumbersSum(3)); // should output 6

diff --git a/1-exercises/E-for-loop/exercise1.js b/1-exercises/E-for-loop/exercise1.js
@@ -6,9 +6,7 @@
 
 
 // Change the below code to use a for loop instead of a while loop.
-let i = 0;
-while(i < 26) {
-    console.log(String.fromCharCode(97 + i));
-    i++;
-}
+
+for(let i = 0; i < 26; i++) console.log(String.fromCharCode(97 + i));
+
 // The output shouldn't change.
diff --git a/1-exercises/E-for-loop/exercise2.js b/1-exercises/E-for-loop/exercise2.js
@@ -27,6 +27,7 @@ const AGES = [
 ];
 
 // TODO - Write for loop code here
+for (let i = 0; i < WRITERS.length; i++) console.log(`${WRITERS[i]} is ${AGES[i]} years old`);
 
 /*
 The output should look something like this:

diff --git a/1-exercises/F-for-of-loop/exercise.js b/1-exercises/F-for-of-loop/exercise.js
@@ -11,6 +11,8 @@ let tubeStations = [
     "Tottenham Court Road"
 ];
 
+for(let tube of tubeStations) console.log(tube);
 
 // TODO Use a for-of loop to capitalise and output each letter in the string seperately.
 let str = "codeyourfuture";
+for(let letter of str) console.log(letter.toUpperCase());
diff --git a/2-mandatory/1-weather-report.js b/2-mandatory/1-weather-report.js
@@ -12,7 +12,7 @@
 */
 
 function getTemperatureReport(cities) {
-    // TODO
+    return cities.map(town => `The temperature in ${town} is ${temperatureService(town)} degrees`)
 }
 
 

diff --git a/2-mandatory/2-retrying-random-numbers.js b/2-mandatory/2-retrying-random-numbers.js
@@ -11,7 +11,15 @@ function generateRandomNumber() {
 
 function getRandomNumberGreaterThan50() {
     // TODO - implement using a do-while loop
+    let rand = generateRandomNumber();
+    do {
+        if(rand > 50) {
+            return rand;
+        }
+    } while(rand <= 50)
+    return rand;
 }
+console.log(getRandomNumberGreaterThan50());
 
 /* ======= TESTS - DO NOT MODIFY ===== */
 

diff --git a/2-mandatory/3-financial-times.js b/2-mandatory/3-financial-times.js
@@ -5,7 +5,9 @@
     Implement the function below, which will return a new array containing only article titles which will fit.
 */
 function potentialHeadlines(allArticleTitles) {
-    // TODO
+    return allArticleTitles.filter(title => {
+        if(title.length <= 65) return title;
+    })
 }
 
 /*
@@ -14,24 +16,26 @@ function potentialHeadlines(allArticleTitles) {
     (you can assume words will always be seperated by a space)
 */
 function titleWithFewestWords(allArticleTitles) {
-    // TODO
+    let num = Math.min(...allArticleTitles.map(title => title.split(" ").length));
+    return allArticleTitles.filter(title => (title.split(" ").length === num) ? title : "").join("");
 }
 
 /*
-    The editor of the FT has realised that headlines which have numbers in them get more clicks!
-    Implement the function below to return a new array containing all the headlines which contain a number.
-    (Hint: remember that you can also loop through the characters of a string if you need to)
+The editor of the FT has realised that headlines which have numbers in them get more clicks!
+Implement the function below to return a new array containing all the headlines which contain a number.
+(Hint: remember that you can also loop through the characters of a string if you need to)
 */
 function headlinesWithNumbers(allArticleTitles) {
-    // TODO
+    return allArticleTitles.filter(titleWithNum => (/\d/.test(titleWithNum)) ? titleWithNum : "");
 }
 
 /*
-    The Financial Times wants to understand what the average number of characters in an article title is.
-    Implement the function below to return this number - rounded to the nearest integer.
+The Financial Times wants to understand what the average number of characters in an article title is.
+Implement the function below to return this number - rounded to the nearest integer.
 */
 function averageNumberOfCharacters(allArticleTitles) {
-    // TODO
+    let arr = allArticleTitles.map(title => title.split("").length);
+    return Math.round(arr.reduce((tot, num) => tot + num)/arr.length);
 }
 
 

diff --git a/2-mandatory/4-stocks.js b/2-mandatory/4-stocks.js
@@ -34,38 +34,45 @@ const CLOSING_PRICES_LAST_5_DAYS_FOR_ALL_STOCKS = [
         Functions can help with this!
 */
 function getAveragePrices(closingPricesForAllStocks) {
-    // TODO
+    return closingPricesForAllStocks.map(priceArr => {
+        return Number((priceArr.reduce((tot, num) => tot + num) / priceArr.length).toFixed(2));
+    })
 }
 
 /*
     We also want to see what the change in price is from the first day to the last day for each stock.
     Implement the below function, which
-        - Takes this CLOSING_PRICES_LAST_5_DAYS_FOR_ALL_STOCKS array as input (remember, it's an array of arrays)
-        - Returns an array containing the price change over the last 5 days for each stock.
-            For example, the first element of the resulting array should contain Apple’s (aapl) price change for the last 5 days.
-            In this example it would be:
-                (Apple's price on the 5th day) - (Apple's price on the 1st day) = 172.99 - 179.19 = -6.2
+    - Takes this CLOSING_PRICES_LAST_5_DAYS_FOR_ALL_STOCKS array as input (remember, it's an array of arrays)
+    - Returns an array containing the price change over the last 5 days for each stock.
+    For example, the first element of the resulting array should contain Apple’s (aapl) price change for the last 5 days.
+    In this example it would be:
+    (Apple's price on the 5th day) - (Apple's price on the 1st day) = 172.99 - 179.19 = -6.2
     The price change value should be rounded to 2 decimal places, and should be a number (not a string)
-*/
+    */
 function getPriceChanges(closingPricesForAllStocks) {
-    // TODO
+    return closingPricesForAllStocks.map(priceArr => {
+        return Number((priceArr[priceArr.length - 1] - priceArr[0]).toFixed(2));
+    })
 }
 
 /*
     As part of a financial report, we want to see what the highest price was for each stock in the last 5 days.
     Implement the below function, which
-        - Takes 2 parameters:
-            - the CLOSING_PRICES_LAST_5_DAYS_FOR_ALL_STOCKS array as input (remember, it's an array of arrays)
-            - the STOCKS array
-        - Returns an array of strings describing what the highest price was for each stock.
-            For example, the first element of the array should be: "The highest price of AAPL in the last 5 days was 180.33"
-            The test will check for this exact string.
+    - Takes 2 parameters:
+    - the CLOSING_PRICES_LAST_5_DAYS_FOR_ALL_STOCKS array as input (remember, it's an array of arrays)
+    - the STOCKS array
+    - Returns an array of strings describing what the highest price was for each stock.
+    For example, the first element of the array should be: "The highest price of AAPL in the last 5 days was 180.33"
+    The test will check for this exact string.
     The stock ticker should be capitalised.
     The price should be shown with exactly 2 decimal places.
-*/
+    */
 function highestPriceDescriptions(closingPricesForAllStocks, stocks) {
-    // TODO
+    return closingPricesForAllStocks.map((priceArr, i) => {
+        return `The highest price of ${stocks[i].toUpperCase()} in the last 5 days was ${Math.max(...priceArr).toFixed(2)}`;
+    })
 }
+console.log(highestPriceDescriptions(CLOSING_PRICES_LAST_5_DAYS_FOR_ALL_STOCKS, STOCKS));
 
 
 /* ======= TESTS - DO NOT MODIFY ===== */

diff --git a/3-extra/1-factorial.js b/3-extra/1-factorial.js
@@ -8,8 +8,10 @@
     Using a loop, complete the function below so it returns the factorial of the number being passed in. 
 */
 
+// Solved it using recursion instead of a loop
 function factorial(input) {
-    // TODO
+    if(input === 1) return 1;
+    return input * factorial(input - 1);
 }
 
 /* ======= TESTS - DO NOT MODIFY ===== */

diff --git a/3-extra/2-array-of-objects.js b/3-extra/2-array-of-objects.js
@@ -10,9 +10,6 @@
     Each title in the resulting array should be the highest rated book in its genre.
 */
 
-function getHighestRatedInEachGenre(books) {
-    // TODO
-}
 
 
 /* ======= Book data - DO NOT MODIFY ===== */
@@ -69,6 +66,23 @@ const BOOKS = [
     },
 ]
 
+function getHighestRatedInEachGenre(books) {
+    let bookTitles = [];
+    let cookingRate = [];
+    let nonFictionRate = [];
+    let childrenRate = [];
+    for(let book of books) {
+        if(book.genre === "cooking") cookingRate.push(book.rating);
+        if(book.genre === "non-fiction") nonFictionRate.push(book.rating);
+        if(book.genre === "children") childrenRate.push(book.rating);
+    }
+    for(let book of books) {
+        if(book.genre === "cooking" && book.rating === Math.max(...cookingRate)) bookTitles.push(book.title);
+        if(book.genre === "non-fiction" && book.rating ===  Math.max(...nonFictionRate)) bookTitles.push(book.title);
+        if(book.genre === "children" && book.rating === Math.max(...childrenRate)) bookTitles.push(book.title);
+    }
+    return bookTitles;
+}
 
 /* ======= TESTS - DO NOT MODIFY ===== */
 test("should return the highest rated book in each genre", () => {

diff --git a/3-extra/3-fibonacci.js b/3-extra/3-fibonacci.js
@@ -14,8 +14,19 @@
 */
 
 function generateFibonacciSequence(n) {
-    // TODO
+    let sequence = [0, 1];
+    let num1 = 0;
+    let num2 = 1;
+    let num3 = 0;
+    for(let i = 0; i < n - 2; i++) {
+        num3 = num1 + num2;
+        sequence.push(num3);
+        num1 = num2;
+        num2 = num3;
+    }
+    return sequence;
 }
+console.log(generateFibonacciSequence(10))
 
 /* ======= TESTS - DO NOT MODIFY ===== */
 test("should return the first 10 numbers in the Fibonacci Sequence", () => {
-Original file line number
+Diff line change
@@ Expand Up / @@ -27,6 +27,7 @@ const AGES = [ @@
     ];
     // TODO - Write for loop code here
+    for (let i = 0; i < WRITERS.length; i++) console.log(`${WRITERS[i]} is ${AGES[i]} years old`);
     /*
     The output should look something like this:
@@ Expand Down @@