London | 26-ITP-May | Rizqah Popoola | Sprint 1 | Data Groups

Sprint-1/fix/median.js

@@ -6,9 +6,25 @@
 // 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 list2 = list
+    .filter((item) => typeof item === "number")
+    .sort((a, b) => a - b);
+  if (list2.length === 0) {
+    return null;
+  }
+  if (list2.length % 2 === 1) {
+    const middleIndex = Math.floor(list2.length / 2);
+    const median = list2[middleIndex];
+    return median;
+  }
+  if (list2.length % 2 === 0) {
+    const middleIndex = Math.floor(list2.length / 2);
+    const median = (list2[middleIndex] + list2[middleIndex - 1]) / 2;
+    return median;
+  }
 }
 
 module.exports = calculateMedian;

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 +1,11 @@
-function dedupe() {}
+function dedupe(input) {
+  const newArray = [];
+  if (input.length === 0) {
+    return [];
+  }
+  for (const i in input)
+    for (const j in input)
+      if (i !== j && !newArray.includes(input[i])) newArray.push(input[i]);
+  return newArray;
+}
+module.exports = dedupe;

Sprint-1/implement/dedupe.test.js

@@ -16,13 +16,23 @@ E.g. dedupe([1, 2, 1]) returns [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 should return the same array`, () => {
+  expect(dedupe(["a", "b", "c"])).toEqual(["a", "b", "c"]);
+  expect(dedupe(["1", "2", "3"])).toEqual(["1", "2", "3"]);
+});
 
 // Given an array of strings or numbers
 // When passed to the dedupe function
-// Then it should return a new array with duplicates removed while preserving the 
+// Then it should return a new array with duplicates removed while preserving the
 // first occurrence of each element from the original array.
+test(`given an array with duplicates, it should return the array with duplicates removed preserving the first occurrence`, () => {
+  expect(dedupe(["b", "c", "a", "b", "c", "b", "c"])).toEqual(["b", "c", "a"]);
+  expect(dedupe(["1", "2", "2", "3", "1", "2", "3"])).toEqual(["1", "2", "3"]);
+});

Sprint-1/implement/max.js

@@ -1,4 +1,14 @@
 function findMax(elements) {
+  if (elements.length === 0) {
+    return -Infinity;
+  }
+  const cleanElements = elements
+    .filter((item) => typeof item === "number")
+    .sort((a, b) => a - b);
+  if (cleanElements.length === 0) {
+    return -Infinity;
+  } else {
+    return cleanElements[cleanElements.length - 1];
+  }
 }
-
 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(`given an empty array, it 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, it should return that number`, () => {
+  expect(findMax([80])).toEqual(80);
+  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 numbers and negative numbers, it should return the largest number overall`, () => {
+  expect(findMax([80, -30, 50, -10, 20, 100, 40])).toEqual(100);
+  expect(findMax([-90, 30, 250, 1, 120, -100, -40])).toEqual(250);
+});
 // 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 negative numbers, it should return the addition of them all`, () => {
+  expect(findMax([-80, -30, -50, -10, -20, -100, -40])).toEqual(-10);
+});
 // 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, it should return the largest decimal number`, () => {
+  expect(findMax([-80.5, -30.1, 50.7, -10, 20.4, 10.3, 60.1])).toEqual(60.1);
+});
 // 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 of numeric and non-numeric values, it should return the largest numeric`, () => {
+  expect(findMax(["hey", 10, "hi", 60, 10])).toEqual(60);
+  expect(
+    findMax(["i", "love", 10, "code", "hi", 80, 60, "your", "future", 10])
+  ).toEqual(80);
+});
 // 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 of non-numeric values, it should return -Infinity`, () => {
+  expect(findMax(["i", "love", "code", "your", "future"])).toEqual(-Infinity);
+});

Sprint-1/implement/sum.js

@@ -1,4 +1,17 @@
 function sum(elements) {
-}
+  if (elements.length === 0) {
+    return 0;
+  }
+  const cleanElements = elements
+    .filter((item) => typeof item === "number")
+    .sort((a, b) => a - b);
+  let sum = 0;
+  if (cleanElements.length === 0) {
+    return 0;
+  } else {
+    for (let i = 0; i < cleanElements.length; i++) sum += cleanElements[i];
 
+    return sum;
+  }
+}
 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, it returns zero`, () => {
+  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 one number, it should return that number`, () => {
+  expect(sum([80])).toEqual(80);
+  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 with negative numbers, it should return the addition of them all`, () => {
+  expect(sum([-80, -30, -50, -10, -20, -100, -40])).toEqual(-330);
+});
 // 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, it should return the total`, () => {
+  expect(sum([-80.5, -30.1, 50.7, -10, 20.4, 10.3, 60.1])).toEqual(20.9);
+});
 // 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 of numeric and non-numeric values, it should return the total of the numeric values`, () => {
+  expect(sum(["hey", 10, "hi", 60, 10])).toEqual(80);
+  expect(
+    sum(["i", "love", 10, "code", "hi", 80, 60, "your", "future", 10])
+  ).toEqual(160);
+});
 // 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 of non-numeric values, it should return zero`, () => {
+  expect(sum(["i", "love", "code", "your", "future"])).toEqual(0);
+});

Sprint-1/refactor/includes.js

@@ -1,13 +1,14 @@
 // 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 item of list) {
+    const element = item;
     if (element === target) {
       return true;
     }
   }
   return false;
 }
+console.log(includes(["a", "b", "c", "d"], "c"));
 
 module.exports = includes;