ITP-JAN-25 | LONDON | Bakytbek Sydykov | Module-Data-Groups | sprint 1

Sprint-1/fix/median.js

@@ -2,10 +2,25 @@
 // Start by running the tests for this function
 // If you're in the Sprint-1 directory, you can run `npm test -- fix` to run the tests in the fix directory
 
-function calculateMedian(list) {
+/*function calculateMedian(list) {
   const middleIndex = Math.floor(list.length / 2);
-  const median = list.splice(middleIndex, 1)[0];
-  return median;
+   if (list.length % 2 === 0) {
+    return (list[middleIndex - 1] + list[middleIndex]) / 2; 
+  } else {
+    return list[middleIndex]; 
+  }
 }
+console.log(calculateMedian([1,2,3,6,7,9]));
+module.exports = calculateMedian;*/
+function calculateMedian(list) {
+  const sortedList = [...list].sort((a, b) => a - b);
+  const middleIndex = Math.floor(sortedList.length / 2);
 
-module.exports = calculateMedian;
+  if (sortedList.length % 2 === 0) {
+    return (sortedList[middleIndex - 1] + sortedList[middleIndex]) / 2;
+  } else {
+    return sortedList[middleIndex];
+  }
+}
+console.log(calculateMedian([1,2,3,6,7,9]));
+module.exports = calculateMedian;

Sprint-1/fix/median.test.js

@@ -16,11 +16,24 @@ describe("calculateMedian", () => {
     expect(calculateMedian([1, 2, 3, 4])).toEqual(2.5);
     expect(calculateMedian([1, 2, 3, 4, 5, 6])).toEqual(3.5);
   });
-
-  test("doesn't modify the input", () => {
+});
+  /*test("doesn't modify the input", () => {
     const list = [1, 2, 3];
     calculateMedian(list);
 
     expect(list).toEqual([1, 2, 3]);
   });
+
+});*/
+test("doesn't modify the input", () => {
+  const list = [1, 2, 3];
+  const originalList = [...list]; 
+
+  calculateMedian(list);
+
+  expect(list).toStrictEqual(originalList); 
 });
+
+
+
+

Sprint-1/implement/dedupe.js

@@ -1 +1,4 @@
-function dedupe() {}
+function dedupe(arr) {
+        return [...new Set(arr)];
+}
+module.exports = dedupe;

Sprint-1/implement/dedupe.test.js

@@ -16,12 +16,25 @@ 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("given an array with no duplicates, it returns a copy of the original array", () => {
+    expect(dedupe([1, 2, 3])).toEqual([1, 2, 3]);
+    expect(dedupe(["a", "b", "c"])).toEqual(["a", "b", "c"]);
+});
+
 // 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("given an array with strings or numbers, it removes the duplicate values, preserving the first occurrence", () => {
+    expect(dedupe(["a", "a", "a", "b", "b", "c"])).toEqual(["a", "b", "c"]);
+    expect(dedupe([5, 1, 1, 2, 3, 2, 5, 8])).toEqual([5, 1, 2, 3, 8]);
+    expect(dedupe([1, 2, 1])).toEqual([1, 2]);
+});

Sprint-1/implement/max.js

@@ -1,4 +1,9 @@
 function findMax(elements) {
+
+    const numericElements = elements.filter((el) => typeof el === "number" && !isNaN(el));
+    if (numericElements.length === 0) return -Infinity;
+    return Math.max(...numericElements);
 }
+
 
 module.exports = findMax;

Sprint-1/implement/max.test.js

@@ -16,28 +16,46 @@ 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("given an empty array, returns -Infinity", () => {
+    expect(findMax([])).toEqual(-Infinity);
+});
 // Given an array with one number
 // When passed to the max function
 // Then it should return that number
 
+test("given an array with one number", () => {
+    expect(findMax([1])).toEqual(1);
+});
+
 // Given an array with both positive and negative numbers
 // When passed to the max function
 // Then it should return the largest number overall
 
+
+test("given an array with both positive and negative numbers, returns the largest number overall", () => {
+    expect(findMax([-10, 3, 20, -5])).toEqual(20);
+});
 // Given an array with just negative numbers
 // When passed to the max function
 // Then it should return the closest one to zero
-
+test("given an array with just negative numbers, returns the closest one to zero", () => {
+    expect(findMax([-10, -3, -20, -5])).toEqual(-3);
+});
 // Given an array with decimal numbers
 // When passed to the max function
 // Then it should return the largest decimal number
-
+test("given an array with decimal numbers, returns the largest decimal number", () => {
+    expect(findMax([1.5, 2.3, 0.8, 2.9])).toEqual(2.9);
+});
 // 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("given an array with non-number values, returns the max and ignores non-numeric values", () => {
+    expect(findMax([10, "hello", undefined, null, 15, {}, 8])).toEqual(15);
+});
 // 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("given an array with only non-number values, returns -Infinity", () => {
+    expect(findMax(["hello", undefined, null, {}, []])).toEqual(-Infinity);
+});

Sprint-1/implement/sum.js

@@ -1,4 +1,10 @@
 function sum(elements) {
+    const numericalelements = elements.filter(el=> typeof el === "number" && !isNaN(el));
+    let total = 0;
+    for (let num of numericalelements) {
+        total = total + num;
+    }
+    return total;
 }
-
+console.log(sum([-2,-3])); 
 module.exports = sum;

Sprint-1/implement/sum.test.js

@@ -13,24 +13,40 @@ 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 an array with just one number", () => {
+    expect(sum([1])).toEqual(1);
+});
 // 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 containing negative numbers", () => {
+expect(sum([-3,-2])).toEqual(-5);
+});
 // 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/float numbers", () => {
+    expect(sum([2.3,3.1,2.5,7.6])).toEqual(15.5)
+});*/
+test("given an array with decimal/float numbers", () => {
+    expect(sum([2.3, 3.1, 2.5, 7.6])).toBeCloseTo(15.5, 10); // 10 is the precision level
+});
 // 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("given an array containing non-number values", () => {
+    expect(sum([true, "Hello",10,10])).toEqual(20)
+});
 // 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("given an array containing non-number values", () => {
+    expect(sum([true, "Hello"])).toEqual(0)
+});

Sprint-1/refactor/includes.js

@@ -1,13 +1,11 @@
 // Refactor the implementation of includes to use a for...of loop
 
 function includes(list, target) {
-  for (let index = 0; index < list.length; index++) {
-    const element = list[index];
+  for (const element of list) { 
     if (element === target) {
       return true;
     }
   }
-  return false;
+  return false; 
 }
-
 module.exports = includes;

prep/mean.js

@@ -0,0 +1,11 @@
+function calculateMean(list){
+let total = 0;
+
+total+=list[0];
+total+=list[1];
+total+=list[2];
+
+let result = total/list.length;
+return result;
+}
+module.exports = calculateMean;

prep/mean.test.js

@@ -0,0 +1,9 @@
+
+const calculateMean = require("./mean.js");
+test("calculates the mean of a list of numbers", () => {
+    const list = [3, 50, 7];
+    const currentOutput = calculateMean(list);
+    const targetOutput = 20;
+
+    expect(currentOutput).toEqual(targetOutput); // 20 is (3 + 50 + 7) / 3
+  });