ZA-ITP-May-2025 | Christian Mayamba | Module-Data-Groups | Week 1

Sprint-1/fix/median.js

@@ -6,9 +6,35 @@
 // or 'list' has mixed values (the function is expected to sort only numbers).
 
 function calculateMedian(list) {
-  const middleIndex = Math.floor(list.length / 2);
-  const median = list.splice(middleIndex, 1)[0];
-  return median;
+  if (!Array.isArray(list)) {
+    return null;
+  }
+
+  const numbersArray = list.filter((item) => typeof item === "number");
+  numbersArray.sort((a, b) => a - b);
+  const middleIndex = Math.floor(numbersArray.length / 2);
+
+  if (
+    list.every(
+      (item) => typeof item === "string" || item === null || item === undefined
+    )
+  ) {
+    return null;
+  }
+
+  if (numbersArray.length % 2 === 0) {
+    const tempMedian =
+      numbersArray[middleIndex] + numbersArray[middleIndex - 1];
+    const median1 = tempMedian / 2;
+    return median1;
+  } else {
+    const middleIndex = Math.floor(numbersArray.length / 2);
+    const median = numbersArray.splice(middleIndex, 1)[0];
+    return median;
+  }
 }
 
 module.exports = calculateMedian;
+
+myArray = calculateMedian(["11", "mango"]);
+console.log(myArray);

Sprint-1/fix/median.test.js

@@ -13,7 +13,8 @@ describe("calculateMedian", () => {
     { input: [1, 2, 3, 4], expected: 2.5 },
     { input: [1, 2, 3, 4, 5, 6], expected: 3.5 },
   ].forEach(({ input, expected }) =>
-    it(`returns the median for [${input}]`, () => expect(calculateMedian(input)).toEqual(expected))
+    it(`returns the median for [${input}]`, () =>
+      expect(calculateMedian(input)).toEqual(expected))
   );
 
   [
@@ -24,7 +25,8 @@ describe("calculateMedian", () => {
     { input: [110, 20, 0], expected: 20 },
     { input: [6, -2, 2, 12, 14], expected: 6 },
   ].forEach(({ input, expected }) =>
-    it(`returns the correct median for unsorted array [${input}]`, () => expect(calculateMedian(input)).toEqual(expected))
+    it(`returns the correct median for unsorted array [${input}]`, () =>
+      expect(calculateMedian(input)).toEqual(expected))
   );
 
   it("doesn't modify the input array [3, 1, 2]", () => {
@@ -33,8 +35,17 @@ describe("calculateMedian", () => {
     expect(list).toEqual([3, 1, 2]);
   });
 
-  [ 'not an array', 123, null, undefined, {}, [], ["apple", null, undefined] ].forEach(val =>
-    it(`returns null for non-numeric array (${val})`, () => expect(calculateMedian(val)).toBe(null))
+  [
+    "not an array",
+    123,
+    null,
+    undefined,
+    {},
+    [],
+    ["apple", null, undefined],
+  ].forEach((val) =>
+    it(`returns null for non-numeric array (${val})`, () =>
+      expect(calculateMedian(val)).toBe(null))
   );
 
   [
@@ -45,6 +56,7 @@ describe("calculateMedian", () => {
     { input: [3, "apple", 1, null, 2, undefined, 4], expected: 2.5 },
     { input: ["banana", 5, 3, "apple", 1, 4, 2], expected: 3 },
   ].forEach(({ input, expected }) =>
-    it(`filters out non-numeric values and calculates the median for [${input}]`, () => expect(calculateMedian(input)).toEqual(expected))
+    it(`filters out non-numeric values and calculates the median for [${input}]`, () =>
+      expect(calculateMedian(input)).toEqual(expected))
   );
 });

Sprint-1/implement/dedupe.js

@@ -1 +1,17 @@
-function dedupe() {}
+function dedupe(array) {
+  if (array.length === 0) {
+    return [];
+  }
+
+  const duplicates = array.filter(
+    (item, index) => array.indexOf(item) !== index
+  );
+
+  const set2 = new Set(duplicates);
+  return array.filter((item) => !set2.has(item));
+}
+
+testVar = [1, 20, "hi", 20, 6, 9, "hey"];
+console.log(dedupe(testVar));
+
+module.exports = dedupe;

Sprint-1/implement/dedupe.test.js

@@ -16,12 +16,20 @@ E.g. dedupe([1, 2, 1]) target output: [1, 2]
 // Given an empty array
 // When passed to the dedupe function
 // Then it should return an empty array
-test.todo("given an empty array, it returns an empty array");
+test("given an empty array, it returns an empty array", () => {
+  expect(dedupe([])).toEqual([]);
+});
 
 // Given an array with no duplicates
 // When passed to the dedupe function
 // Then it should return a copy of the original array
+test("array with no duplicates, it returns a copy of the array", () => {
+  expect(dedupe([10, 20, 30])).toEqual([10, 20, 30]);
+});
 
 // Given an array with strings or numbers
 // When passed to the dedupe function
 // Then it should remove the duplicate values, preserving the first occurence of each element
+test("array with strings and numbers, it should remove duplicates", () => {
+  expect(dedupe([10, "hi", "hey", 20, "hey", 30])).toEqual([10, "hi", 20, 30]);
+});

Sprint-1/implement/max.js

@@ -1,4 +1,20 @@
 function findMax(elements) {
+  if (elements.length === 0) {
+    return "-Infinity";
+  }
+
+  if (elements.every((item) => typeof item === "string")) {
+    return "undefined";
+  }
+
+  const numbersArray = elements.filter((item) => typeof item === "number");
+  elements.sort((a, b) => a - b);
+  const maxNum = elements[elements.length - 1];
+
+  return maxNum;
 }
+const verArray = [-5, -10, -65, -6];
+
+console.log(findMax(verArray));
 
 module.exports = findMax;

Sprint-1/implement/max.test.js

@@ -16,28 +16,48 @@ const findMax = require("./max.js");
 // When passed to the max function
 // Then it should return -Infinity
 // Delete this test.todo and replace it with a test.
-test.todo("given an empty array, returns -Infinity");
+test("Empty array should return -Infinity", () => {
+  expect(findMax([])).toEqual("-Infinity");
+});
 
 // Given an array with one number
 // When passed to the max function
 // Then it should return that number
+test("Array with number should return that number", () => {
+  expect(findMax([10])).toEqual(10);
+});
 
 // Given an array with both positive and negative numbers
 // When passed to the max function
 // Then it should return the largest number overall
+test("Negative and positive numbers should return the largest overall", () => {
+  expect(findMax([10, -5, 58, -56])).toEqual(58);
+});
 
 // Given an array with just negative numbers
 // When passed to the max function
 // Then it should return the closest one to zero
+test("Negative numbers should return the closest to zero", () => {
+  expect(findMax([-5, -10, -65, -6])).toEqual(-5);
+});
 
 // Given an array with decimal numbers
 // When passed to the max function
 // Then it should return the largest decimal number
+test("Decimal numbers should return the largest one", () => {
+  expect(findMax([0.5, 10.5, 56.9, 3.5])).toEqual(56.9);
+});
 
 // Given an array with non-number values
 // When passed to the max function
 // Then it should return the max and ignore non-numeric values
+test("Non-numeric values should be ignored and return the max numeric", () => {
+  expect(findMax(["hey", 10, "hi", 60, 10])).toEqual(60);
+});
 
 // Given an array with only non-number values
 // When passed to the max function
 // Then it should return the least surprising value given how it behaves for all other inputs
+test("Only non-number values should return undefined", () => {
+  expect(findMax(["hey", "love", "hi", "hate"])).toEqual("undefined");
+});

Sprint-1/implement/sum.js

@@ -1,4 +1,21 @@
 function sum(elements) {
+  if (elements.length === 0) {
+    return 0;
+  }
+
+  if (elements.every((item) => typeof item === "string")) {
+    return "undefined";
+  }
+
+  const numbersArray = elements.filter((item) => typeof item === "number");
+
+  let sum1 = 0;
+  for (let i = 0; i < numbersArray.length; i++) {
+    sum1 += numbersArray[i];
+  }
+  return sum1;
 }
+testVar = [10, "jesus", 20, "hi"];
+console.log(sum(testVar));
 
 module.exports = sum;

Sprint-1/implement/sum.test.js

@@ -13,24 +13,41 @@ const sum = require("./sum.js");
 // Given an empty array
 // When passed to the sum function
 // Then it should return 0
-test.todo("given an empty array, returns 0")
+test("given an empty array, returns 0", () => {
+  expect(sum([])).toEqual(0);
+});
 
 // Given an array with just one number
 // When passed to the sum function
 // Then it should return that number
+test("given array with one number, returns that number", () => {
+  expect(sum([10])).toEqual(10);
+});
 
 // Given an array containing negative numbers
 // When passed to the sum function
 // Then it should still return the correct total sum
+test("given an array with negative numbers, returns the total sum", () => {
+  expect(sum([-10, -5, -50])).toEqual(-65);
+});
 
 // Given an array with decimal/float numbers
 // When passed to the sum function
 // Then it should return the correct total sum
+test("given an array with decimal numbers, returns the total sum", () => {
+  expect(sum([10.5, 65.9, 50.8])).toEqual(127.2);
+});
 
 // Given an array containing non-number values
 // When passed to the sum function
 // Then it should ignore the non-numerical values and return the sum of the numerical elements
+test("Non-numerical values should be ignored and return the sum of the rest", () => {
+  expect(sum(["hey", 10, "hi", 60, 10])).toEqual(80);
+});
 
 // Given an array with only non-number values
 // When passed to the sum function
 // Then it should return the least surprising value given how it behaves for all other inputs
+test("Only non-number values should return undefined", () => {
+  expect(sum(["hey", "love", "hi", "hate"])).toEqual("undefined");
+});