London | 26-ITP-May | | Sprint 1 | Sprint 1 exercise/implement

Sprint-1/fix/median.js

@@ -1,13 +1,24 @@
-// Fix this implementation
-// 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) {
+  const numbers = [];
+  for (const x of list) {
+    if (typeof x === "number") {
+      numbers.push(x);
+    }
+  }
+  if (numbers.length === 0 || list.length === 0) {
+    return null;
+  }
 
-// Hint: Please consider scenarios when 'list' doesn't have numbers (the function is expected to return null)
-// or 'list' has mixed values (the function is expected to sort only numbers).
+  numbers.sort((a, b) => a - b);
+  const middleIndex = Math.floor(numbers.length / 2);
 
-function calculateMedian(list) {
-  const middleIndex = Math.floor(list.length / 2);
-  const median = list.splice(middleIndex, 1)[0];
+  if (numbers.length % 2 === 0) {
+    const left = numbers[middleIndex - 1];
+    const right = numbers[middleIndex];
+    return (left + right) / 2;
+  }
+
+  const median = numbers[middleIndex];
   return median;
 }
 

Sprint-1/implement/dedupe.js

@@ -1 +1,6 @@
-function dedupe() {}
+function dedupe() {
+  const newDedupe = [...new Set(value)];
+  return newDedupe;
+}
+
+module.exports = dedupe;

Sprint-1/implement/dedupe.test.js

@@ -1,28 +1,15 @@
 const dedupe = require("./dedupe.js");
-/*
-Dedupe Array
 
-📖 Dedupe means **deduplicate**
+test("given an empty array, it returns an empty array", () => {
+  expect(dedupe([])).toEqual([]);
+});
 
-In this kata, you will need to deduplicate the elements of an array
+test("given an array with unique elements, it returns the same array", () => {
+  expect(dedupe([2, 1, 4, "2", "d", "g"])).toEqual([2, 1, 4, "2", "d", "g"]);
+});
 
-E.g. dedupe(['a','a','a','b','b','c']) returns ['a','b','c']
-E.g. dedupe([5, 1, 1, 2, 3, 2, 5, 8]) returns [5, 1, 2, 3, 8]
-E.g. dedupe([1, 2, 1]) returns [1, 2]
-*/
-
-// Acceptance Criteria:
-
-// 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");
-
-// Given an array with no duplicates
-// When passed to the dedupe function
-// Then it should return a copy of the original array
-
-// 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 
-// first occurrence of each element from the original array.
+test("given an array of strings or numbers then it should return new array with duplicates removed", () => {
+  expect(dedupe([2, 2, 4, 2, 3, 4, 8, 5, 4, 1, 9])).toEqual([
+    2, 4, 3, 8, 5, 1, 9,
+  ]);
+});

Sprint-1/implement/max.js

@@ -1,4 +1,6 @@
 function findMax(elements) {
+  elements = elements.filter((x) => typeof x === "number");
+  return Math.max(...elements);
 }
 
 module.exports = findMax;

Sprint-1/implement/max.test.js

@@ -1,43 +1,33 @@
-/* Find the maximum element of an array of numbers
-
-In this kata, you will need to implement a function that find the largest numerical element of an array.
-
-E.g. max([30, 50, 10, 40]), target output: 50
-E.g. max(['hey', 10, 'hi', 60, 10]), target output: 60 (sum ignores any non-numerical elements)
-
-You should implement this function in max.js, and add tests for it in this file.
-
-We have set things up already so that this file can see your function from the other file.
-*/
-
 const findMax = require("./max.js");
 
-// Given an empty array
-// 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 array with only +ve numbers and should return the largest of them", () => {
+  expect(findMax([2, 4, 2, 1, 5])).toEqual(5);
+});
+
+test("Given an 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("Given an array with one number only  and it should return that number", () => {
+  expect(findMax([7])).toEqual(7);
+});
 
-// 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 and it should return the largest number", () => {
+  expect(findMax([1, -3, -2, 3, 4])).toEqual(4);
+});
 
-// 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 and it should return the largest number", () => {
+  expect(findMax([-2, -5, -5, -3, -10])).toEqual(-2);
+});
 
-// 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 and it should return the largest decimal numbers", () => {
+  expect(findMax([2.7, 2.01, 4.4, 5.2])).toEqual(5.2);
+});
 
-// 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 a mix of non-numeric values and numeric values and it should return the largest from only the numeric values and ignore the non-numeric ones", () => {
+  expect(findMax([2, "a", 8, "12", 8.1])).toEqual(8.1);
+});
 
-// 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-numeric values and it should return -Infinity", () => {
+  expect(findMax(["a", "e", "I", "o", "U"])).toEqual(-Infinity);
+});

Sprint-1/implement/sum.js

@@ -1,4 +1,10 @@
 function sum(elements) {
+  let total = 0;
+  elements = elements.filter((x) => typeof x === "number");
+  for (let i = 0; i < elements.length; i++) {
+    total += elements[i];
+  }
+  return total;
 }
 
 module.exports = sum;

Sprint-1/implement/sum.test.js

@@ -1,36 +1,25 @@
-/* Sum the numbers in an array
-
-In this kata, you will need to implement a function that sums the numerical elements of an array
-
-E.g. sum([10, 20, 30]), target output: 60
-E.g. sum(['hey', 10, 'hi', 60, 10]), target output: 80 (ignore any non-numerical elements)
-*/
-
 const sum = require("./sum.js");
 
-// Acceptance Criteria:
-
-// 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 an empty array", () => {
+  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 to the sum function Then it should return that number", () => {
+  expect(sum([3])).toEqual(3);
+});
 
-// 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 to the sum function then it should return the correct total", () => {
+  expect(sum([1, -1, -2, -3])).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 should return the correct total sum", () => {
+  expect(sum([2, 2.5])).toEqual(4.5);
+});
 
-// 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 non-number value should return the correct total of only the numeric ones", () => {
+  expect(sum([2, "2", "a", "b", 3])).toEqual(5);
+});
 
-// 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 non-number value should return 0", () => {
+  expect(sum(["a", "c", "f", "3"])).toEqual(0);
+});