ZA2-Chezlin Benson-javascript-Core-1-Week3-Exercises-Mandatory-Extra-Completed

1-exercises/A-undefined/exercise.js

@@ -12,6 +12,8 @@
 // Example 1
 let a;
 console.log(a);
+//a was not assigned any value
+
 
 
 // Example 2
@@ -21,6 +23,7 @@ function sayHello() {
 
 let hello = sayHello();
 console.log(hello);
+//The variable "sayHello" were not passed any value
 
 
 // Example 3
@@ -29,8 +32,12 @@ function sayHelloToUser(user) {
 }
 
 sayHelloToUser();
+//Again the function "sayHelloToUser", has not been passed any arguments
 
 
 // Example 4
 let arr = [1,2,3];
 console.log(arr[3]);
+// In this example above, there are no index value 3 in the array.
+// Arrays work with zero indexing and therefore a index of 3 would indicate a fourth value in the array
+// and this array only has three values and result to an undefined error. 

1-exercises/B-while-loop/exercise.js

@@ -7,6 +7,14 @@
 
 function evenNumbers(n) {
     // TODO
+    let i = 0;
+    let evenArray = [];
+
+    while (i < n) {
+       evenArray.push(i * 2);
+       i++; 
+    }
+    console.log(evenArray.join(', '));
 }
 
 evenNumbers(3); // should output 0,2,4

1-exercises/C-while-loop-with-array/exercise.js

@@ -17,7 +17,19 @@ const BIRTHDAYS = [
 ];
 
 function findFirstJulyBDay(birthdays) {
-    // TODO
+    //TODO
+    let i = 0;
+    let myBdayCheck;
+
+    while (i < birthdays.length - 1) {
+          myBdayCheck = birthdays[i];
+
+        if (myBdayCheck.startsWith("July")) {
+            return myBdayCheck;
+        }
+        i++;
+    }   
 }
 
+
 console.log(findFirstJulyBDay(BIRTHDAYS)); // should output "July 11th"

1-exercises/D-do-while/exercise.js

@@ -8,6 +8,14 @@
 
 function evenNumbersSum(n) {
     // TODO
+    let i = 0;
+    let sum = 0;
+
+    do {
+       sum = sum + i * 2;       
+       i++; 
+    } while (i < n);
+    return sum;
 }
 
 console.log(evenNumbersSum(3)); // should output 6

1-exercises/E-for-loop/exercise1.js

@@ -6,9 +6,9 @@
 
 
 // Change the below code to use a for loop instead of a while loop.
-let i = 0;
-while(i < 26) {
+
+for (let i = 0; i < 26; i++) {
     console.log(String.fromCharCode(97 + i));
-    i++;
+
 }
 // The output shouldn't change.

1-exercises/E-for-loop/exercise2.js

@@ -28,6 +28,11 @@ 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:
 

1-exercises/F-for-of-loop/exercise.js

@@ -11,6 +11,14 @@ let tubeStations = [
     "Tottenham Court Road"
 ];
 
+for (let stations of tubeStations) {
+    console.log(stations);
+}
+
 
 // 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());
+}

2-mandatory/1-weather-report.js

@@ -7,15 +7,23 @@
     Implement the function below:
         - take the array of cities as a parameter
         - return an array of strings, which is a statement about the temperature of each city.
-            For example, "The temperature in London is 10 degrees"
+            For example, ""
         - Hint: you can call the temperatureService function from your function
 */
 
 function getTemperatureReport(cities) {
     // TODO
+
+let tempArray = [];
+for (let city of cities) {
+    tempArray.push(`The temperature in ${city} is ${temperatureService(city)} degrees`);
+}
+return tempArray;
+
 }
 
 
+
 /* ======= TESTS - DO NOT MODIFY ===== */
 
 function temperatureService(city) {

2-mandatory/2-retrying-random-numbers.js

@@ -11,6 +11,12 @@ function generateRandomNumber() {
 
 function getRandomNumberGreaterThan50() {
     // TODO - implement using a do-while loop
+    let num;
+    do {
+        (num = generateRandomNumber());
+    } while (num <= 50);
+
+    return num;
 }
 
 /* ======= TESTS - DO NOT MODIFY ===== */

2-mandatory/3-financial-times.js

@@ -6,6 +6,16 @@
 */
 function potentialHeadlines(allArticleTitles) {
     // TODO
+    let fitTitles = [];
+    for (let articleTitle of allArticleTitles) {
+
+        if (articleTitle.length <= 65) {
+            fitTitles.push(articleTitle);
+        }
+
+    }
+
+    return fitTitles;
 }
 
 /*
@@ -15,7 +25,26 @@ function potentialHeadlines(allArticleTitles) {
 */
 function titleWithFewestWords(allArticleTitles) {
     // TODO
-}
+       let fewest = allArticleTitles[0];
+       let prevCount = allArticleTitles[0].split(" ").length;
+
+        for(let i = 1; i < allArticleTitles.length; i++) {
+
+            let currentCount = allArticleTitles[i].split(" ").length;
+
+            if(currentCount < prevCount) {
+                fewest = allArticleTitles[i];
+            }
+
+            prevCount = currentCount;            
+        }   
+
+    return fewest;
+
+    }
+
+
+
 
 /*
     The editor of the FT has realised that headlines which have numbers in them get more clicks!
@@ -24,14 +53,44 @@ function titleWithFewestWords(allArticleTitles) {
 */
 function headlinesWithNumbers(allArticleTitles) {
     // TODO
-}
+    let numberHeadlines = [];
+
+        for(let i = 0; i < allArticleTitles.length; i++) {
+            let titleChecker = allArticleTitles[i];
+
+            for( let j = 0; j < titleChecker.length; j++) {
+
+                let charChecker = Number(titleChecker[j])
+
+                if(Number.isInteger(charChecker) && charChecker > 0 ){
+                    numberHeadlines.push(titleChecker);
+                    break;
+                }
+            }
+        }
+        return numberHeadlines;
+    } 
+
+
+
 
 /*
     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 averageNum = 0;
+    let titleSum = 0;
+
+    for (let i = 0; i < allArticleTitles.length; i++){
+        titleSum += allArticleTitles[i].length; 
+    }
+
+    let averageNum = titleSum / allArticleTitles.length;
+
+    return Math.round(averageNum);
 }
 
 

2-mandatory/4-stocks.js

@@ -35,6 +35,17 @@ const CLOSING_PRICES_LAST_5_DAYS_FOR_ALL_STOCKS = [
 */
 function getAveragePrices(closingPricesForAllStocks) {
     // TODO
+
+    let averageStockArr = [];
+    for(let i = 0; i < closingPricesForAllStocks.length; i++){
+        let sumOfStock = 0;
+        for( let j = 0; j < closingPricesForAllStocks[i].length; j++ ) {
+            sumOfStock += closingPricesForAllStocks[i][j];            
+        }
+        let averageSum = sumOfStock / closingPricesForAllStocks.length;
+            averageStockArr.push(parseFloat(averageSum.toFixed(2)));
+    }
+    return averageStockArr;
 }
 
 /*
@@ -49,6 +60,17 @@ function getAveragePrices(closingPricesForAllStocks) {
 */
 function getPriceChanges(closingPricesForAllStocks) {
     // TODO
+
+    let priceChangeArr = [];
+
+    for(let i = 0; i < closingPricesForAllStocks.length; i++){
+        let last = closingPricesForAllStocks[i].length - 1;
+        let firstPrice = closingPricesForAllStocks[i][0];
+        let lastPrice = closingPricesForAllStocks[i][last];
+        let averagePriceSum = lastPrice - firstPrice;
+        priceChangeArr.push(parseFloat(averagePriceSum.toFixed(2)));
+    }
+    return priceChangeArr;
 }
 
 /*
@@ -65,9 +87,24 @@ function getPriceChanges(closingPricesForAllStocks) {
 */
 function highestPriceDescriptions(closingPricesForAllStocks, stocks) {
     // TODO
+    let highestStockPrice = [];
+
+    for(let i = 0; i < closingPricesForAllStocks.length; i++){
+        let highTotal = 0;
+        for(let j = 0; j < closingPricesForAllStocks[i].length; j++){
+            if(closingPricesForAllStocks[i][j] > highTotal){
+                highTotal = closingPricesForAllStocks[i][j];
+            }
+        }
+        highestStockPrice.push(`The highest price of ${stocks[i].toUpperCase()} in the last 5 days was ${highTotal.toFixed(2)}`);
+ }
+
+
+    return highestStockPrice;
 }
 
 
+
 /* ======= TESTS - DO NOT MODIFY ===== */
 test("should return the average price for each stock", () => {
     expect(getAveragePrices(CLOSING_PRICES_LAST_5_DAYS_FOR_ALL_STOCKS)).toEqual(

3-extra/1-factorial.js

@@ -9,19 +9,26 @@
 */
 
 function factorial(input) {
-    // TODO
+  // TODO
+
+  let sum = input;
+
+  for (let i = input - 1; i >= 1; i--) {
+    sum = sum * i;
+  }
+  return sum;
 }
 
 /* ======= TESTS - DO NOT MODIFY ===== */
 
 test("3! should be 6", () => {
-    expect(factorial(3)).toEqual(6);
+  expect(factorial(3)).toEqual(6);
 });
 
 test("5! should be 120", () => {
-    expect(factorial(5)).toEqual(120);
+  expect(factorial(5)).toEqual(120);
 });
 
 test("10! should be 3628800", () => {
-    expect(factorial(10)).toEqual(3628800);
+  expect(factorial(10)).toEqual(3628800);
 });