Week 3

week-3/1-exercises/A-array-find/exercise.js

@@ -5,9 +5,12 @@
 
 // write your code here
 
-var names = ["Rakesh", "Antonio", "Alexandra", "Andronicus", "Annam", "Mikey", "Anastasia", "Karim", "Ahmed"];
+function isLongNameThatStartsWithA(name) {
+  return name[0] === "A"  &&  name.length > 7;
+}
 
-var longNameThatStartsWithA = findLongNameThatStartsWithA(names);
+var names = ["Rakesh", "Antonio", "Alexandra", "Andronicus", "Annam", "Mikey", "Anastasia", "Karim", "Ahmed"];
+var longNameThatStartsWithA = names.find(isLongNameThatStartsWithA);
 
 console.log(longNameThatStartsWithA);
 

week-3/1-exercises/B-array-some/exercise.js

@@ -15,7 +15,15 @@ var pairsByIndex = [[0, 3], [1, 2], [2, 1], null, [3, 0]];
 var students = ["Islam", "Lesley", "Harun", "Rukmini"];
 var mentors = ["Daniel", "Irina", "Mozafar", "Luke"];
 
+function isNull(x) {
+  return x === null;
+}
+
 var pairs = pairsByIndex.map(function(indexes) {
+  if(pairsByIndex.some(isNull)) {
+    console.log("Error: null value");
+    process.exit(1);
+  }
   var student = students[indexes[0]];
   var mentor = mentors[indexes[1]];
   return [student, mentor];

week-3/1-exercises/C-array-every/exercise.js

@@ -5,7 +5,9 @@
 var students = ["Omar", "Austine", "Dany", "Swathi", "Lesley", "Rukmini"];
 var group = ["Austine", "Dany", "Swathi", "Daniel"];
 
-var groupIsOnlyStudents; // complete this statement
+var groupIsOnlyStudents = group.every(function isStudent(member) {
+  return students.includes(member);
+});
 
 if (groupIsOnlyStudents) {
   console.log("The group contains only students");

week-3/1-exercises/D-array-filter/exercise.js

@@ -8,7 +8,14 @@
 
 var pairsByIndexRaw = [[0, 3], [1, 2], [2, 1], null, [1], false, "whoops"];
 
-var pairsByIndex; // Complete this statement
+var pairsByIndex = pairsByIndexRaw.filter(function (i) {
+  if (typeof(i) !== "object"  ||  i === null) {
+    return false;}
+  else if (i.length !== 2) {
+    return false;}
+  else {
+    return true;}
+  });
 
 var students = ["Islam", "Lesley", "Harun", "Rukmini"];
 var mentors = ["Daniel", "Irina", "Mozafar", "Luke"];

week-3/1-exercises/E-array-map/exercise.js

@@ -3,3 +3,17 @@
 
 var numbers = [0.1, 0.2, 0.3, 0.4, 0.5];
 
+// method 1
+var largerNumbers = numbers.map(function (x) {
+    return x * 100;
+});
+console.log(largerNumbers);
+
+
+//method 2
+function multiplyBy100(x) {
+    return x * 100;
+}
+
+var largerNumbers2 = numbers.map(multiplyBy100);
+console.log(largerNumbers2);

week-3/1-exercises/F-array-forEach/exercise.js

@@ -9,6 +9,18 @@
 
 var arr = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15];
 
+arr.forEach(function (n) {
+  if (n % 3 === 0  &&  n % 5 === 0) {
+    console.log("FizzBuzz");}
+  else if (n % 3 === 0) {
+    console.log("Fizz");}
+  else if (n % 5 === 0) {
+    console.log("Buzz");}
+  else {
+    console.log(n);}
+});
+
+
 /* EXPECTED OUTPUT */
 
 /*

week-3/1-exercises/G-array-methods/exercise.js

@@ -4,7 +4,7 @@
 */
 
 var numbers = [3, 2, 1];
-var sortedNumbers; // complete this statement
+var sortedNumbers = numbers.sort(function(a, b) {return a - b}); // complete this statement
 
 /* 
   DO NOT EDIT BELOW THIS LINE

week-3/1-exercises/G-array-methods/exercise2.js

@@ -7,7 +7,7 @@
 var mentors = ["Daniel", "Irina", "Rares"];
 var students = ["Rukmini", "Abdul", "Austine", "Swathi"];
 
-var everyone; // complete this statement
+var everyone = mentors.concat(students);
 
 /* 
   DO NOT EDIT BELOW THIS LINE

week-3/1-exercises/H-array-methods-2/exercise.js

@@ -15,8 +15,8 @@ var everyone = [
   "Swathi"
 ];
 
-var firstFive; // complete this statement
-var lastFive; // complete this statement
+var firstFive = everyone.slice(0, 5); // complete this statement
+var lastFive = everyone.slice(-5); // complete this statement
 
 /* 
   DO NOT EDIT BELOW THIS LINE

week-3/1-exercises/H-array-methods-2/exercise2.js

@@ -7,7 +7,11 @@
   Tip: use the string method .split() and the array method .join()
 */
 
-function capitalise(str) {}
+function capitalise(str) {
+  str = str.split("");
+  str[0] = str[0].toUpperCase();
+  return str.join("");
+}
 
 /* 
   DO NOT EDIT BELOW THIS LINE

week-3/1-exercises/H-array-methods-2/exercise3.js

@@ -7,7 +7,7 @@
 var ukNations = ["Scotland", "Wales", "England", "Northern Ireland"];
 
 function isInUK(country) {
-  return; // complete this statement
+  return ukNations.includes(country);
 }
 
 /* 

week-3/2-mandatory/1-oxygen-levels.js

@@ -2,39 +2,60 @@
 Many years into the future, a team of Space Voyagers find their ship is low on Oxygen and need to dock
 somewhere safe while they call home for help.
 
-Their computer detects a list of nearby planets that have Oxygen in their atmosphere.
+Their computer detects a list of nearby planets that have Oxygen in their atmosphere. It has produced an array of their Oxygen levels.
 
-To be safe, they need to land on the first unamed planet that has Oxygen levels between 19.5% and 23.5%.
+To be safe to land on, a planet needs to have an Oxygen level between 19.5% and 23.5%.
 
-Write a function that finds the oxygen level of the first safe planet - Oxygen between 19.5% and 23.5%
+Write a function that finds the first safe oxygen level in the array - Oxygen between 19.5% and 23.5%
 */
 
-function safeLevels() {
+function safeLevels(oxygenLevel) {
+    oxygenLevel = oxygenLevel.map(function (percentage) {   //removes "%" from the string and converts it to a number 
+        return Number(percentage.replace("%", ""));
+    });
 
+    for(let i = 0; i < oxygenLevel.length; ++i) {
+        if (oxygenLevel[i] > 19.5  &&  oxygenLevel[i] < 23.5) {
+            return String(oxygenLevel[i]).concat("%");      //converts the number back to string and appends "%"
+        }
+    }
+
+    return -1 // Error: no safe oxygen levels found
 }
 
 /* ======= TESTS - DO NOT MODIFY ===== */
 
-const oxygenLevels1 = ["24.2%", "11.3%", "19.9%", "23.1%", "29.3%", "20.2%"]
-const oxygenLevels2 = ["30.8%", "23.5%", "18.8%", "19.5%", "20.2%", "31.6%"]
+const oxygenLevels1 = ["24.2%", "11.3%", "19.9%", "23.1%", "29.3%", "20.2%"];
+const oxygenLevels2 = ["30.8%", "23.5%", "18.8%", "19.5%", "20.2%", "31.6%"];
+const oxygenLevels3 = ["200%", "21.1%"];
+
+const util = require('util');
 
-function test(test_name, expr) {
+function test(test_name, actual, expected) {
     let status;
-    if (expr) {
-      status = "PASSED";
+    if (actual === expected) {
+        status = "PASSED";
     } else {
-      status = "FAILED";
+        status = `FAILED: expected: ${util.inspect(expected)} but your function returned: ${util.inspect(actual)}`;
     }
-  
+
     console.log(`${test_name}: ${status}`);
 }
 
 test(
-    "safeLevels function works - case 2",
-    safeLevels(oxygenLevels1) === "19.9%"
+    "safeLevels function works - case 1",
+    safeLevels(oxygenLevels1),
+    "19.9%"
 );
 
 test(
     "safeLevels function works - case 2",
-    safeLevels(oxygenLevels2) === "20.2%"
-);
+    safeLevels(oxygenLevels2),
+    "20.2%"
+);
+
+test(
+    "safeLevels function works - case 3",
+    safeLevels(oxygenLevels3),
+    "21.1%"
+);

week-3/2-mandatory/2-bush-berries.js

@@ -10,25 +10,41 @@
   Use the tests to confirm which message to return
 */
 
-function bushChecker() {
-
+function bushChecker(bush) {
+  for (let i = 0; i < bush.length; ++i) {
+    if (bush[i] !== "pink") {
+      return "Toxic! Leave bush alone!";
+    }
+  }
+  return "Bush is safe to eat from";
 }
 
 /* ======= TESTS - DO NOT MODIFY ===== */
 
 let bushBerryColours1 = ["pink", "pink", "pink", "neon", "pink", "transparent"]
 let bushBerryColours2 = ["pink", "pink", "pink", "pink"]
 
-function test(test_name, expr) {
-  let status;
-  if (expr) {
-    status = "PASSED";
-  } else {
-    status = "FAILED";
-  }
+const util = require('util');
+
+function test(test_name, actual, expected) {
+    let status;
+    if (actual === expected) {
+        status = "PASSED";
+    } else {
+        status = `FAILED: expected: ${util.inspect(expected)} but your function returned: ${util.inspect(actual)}`;
+    }
 
-  console.log(`${test_name}: ${status}`);
+    console.log(`${test_name}: ${status}`);
 }
 
-test("bushChecker funtion works - case 1", bushChecker(bushBerryColours1) === "Toxic! Leave bush alone!")
-test("bushChecker funtion works - case 1", bushChecker(bushBerryColours2) === "Bush is safe to eat from")
+test(
+  "bushChecker funtion works - case 1",
+  bushChecker(bushBerryColours1),
+  "Toxic! Leave bush alone!"
+);
+
+test(
+  "bushChecker funtion works - case 1",
+  bushChecker(bushBerryColours2),
+  "Bush is safe to eat from"
+);

week-3/2-mandatory/3-space-colonies.js

@@ -8,8 +8,14 @@
   NOTE: don't include any element that is not a "family".
 */
 
-function colonisers() {
-
+function colonisers(voyagers) {
+  let families = [];
+  for (let i = 0; i < voyagers.length; ++i) {
+    if (voyagers[i].includes("family")  &&  voyagers[i][0] === "A") {
+      families.push(voyagers[i]);
+    }
+  }
+  return families;
 }
 
 /* ======= TESTS - DO NOT MODIFY ===== */
@@ -29,29 +35,21 @@ const voyagers = [
   "Archer family"
 ];
 
-function arraysEqual(a, b) {
-  if (a === b) return true;
-  if (a == null || b == null) return false;
-  if (a.length != b.length) return false;
-
-  for (let i = 0; i < a.length; ++i) {
-    if (a[i] !== b[i]) return false;
-  }
+const util = require('util');
 
-  return true;
-}
-
-function test(test_name, expr) {
-  let status;
-  if (expr) {
-    status = "PASSED";
-  } else {
-    status = "FAILED";
-  }
+function test(test_name, actual, expected) {
+    let status;
+    if (util.isDeepStrictEqual(actual, expected)) {
+        status = "PASSED";
+    } else {
+        status = `FAILED: expected: ${util.inspect(expected)} but your function returned: ${util.inspect(actual)}`;
+    }
 
-  console.log(`${test_name}: ${status}`);
+    console.log(`${test_name}: ${status}`);
 }
 
-test("colonisers function works",
-  arraysEqual(colonisers(voyagers), ["Adam family", "Avery family", "Archer family"])
-)
+test(
+  "colonisers function works",
+  colonisers(voyagers),
+  ["Adam family", "Avery family", "Archer family"]
+)

week-3/2-mandatory/4-eligible-students.js

@@ -7,8 +7,16 @@
   - Returns an array containing only the names of the who have attended AT LEAST 8 classes
 */
 
-function eligibleStudents() {
+function eligibleStudents(students) {
+  let eligibleStudents = [];
 
+  for (let i = 0; i < students.length; ++i) {
+    if (students[i][1] >= 8) {
+      eligibleStudents.push(students[i][0]);
+    }
+  }
+
+  return eligibleStudents;
 }
 
 /* ======= TESTS - DO NOT MODIFY ===== */
@@ -22,31 +30,20 @@ const attendances = [
   ["Nina", 10]
 ]
 
-function arraysEqual(a, b) {
-    if (a === b) return true;
-    if (a == null || b == null) return false;
-    if (a.length != b.length) return false;
-
-    for (let i = 0; i < a.length; ++i) {
-      if (a[i] !== b[i]) return false;
-    }
-
-    return true;
-}
+const util = require('util');
 
-function test(test_name, expr) {
+function test(test_name, actual, expected) {
     let status;
-    if (expr) {
-      status = "PASSED";
+    if (util.isDeepStrictEqual(actual, expected)) {
+        status = "PASSED";
     } else {
-      status = "FAILED";
+        status = `FAILED: expected: ${util.inspect(expected)} but your function returned: ${util.inspect(actual)}`;
     }
-  
+
     console.log(`${test_name}: ${status}`);
 }
 
 test("eligibleStudents function works",
-  arraysEqual(
-    eligibleStudents(attendances), ["Ahmed", "Clement", "Tayoa", "Nina"]
-  )
-)
+  eligibleStudents(attendances),
+  ["Ahmed", "Clement", "Tayoa", "Nina"]
+);