West-Midlands | 26-ITP-May | Maryam Janjua | Sprint 1| Fix, Implement and Refactor Exercises

Sprint-1/fix/median.js

@@ -5,10 +5,24 @@
 // 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).
 
-function calculateMedian(list) {
-  const middleIndex = Math.floor(list.length / 2);
-  const median = list.splice(middleIndex, 1)[0];
-  return median;
+function calculateMedian(list){
+  if(!Array.isArray(list)){
+    return null;
+  }
+  const num = [];
+  for(let i = 0; i < list.length ; i++){
+    if (typeof list[i] === "number"){
+      num.push(list[i]);
+    }
+  }
+  if (num.length === 0){
+    return null;
+  }
+  num.sort((a, b) => a - b);
+  const middleIndex = Math.floor(num.length / 2);
+  if (num.length % 2 === 1){
+    return num[middleIndex];
+  }
+  return (num[middleIndex-1] + num[middleIndex])/2;
 }
-
 module.exports = calculateMedian;

Sprint-1/implement/dedupe.js

@@ -1 +1,10 @@
-function dedupe() {}
+function dedupe(array) {
+    const result = [];
+    for(let i = 0; i < array.length ; i++){
+        if(!result.includes(array[i])){
+           result.push(array[i]);
+        }
+    }
+    return result;
+}
+module.exports = dedupe;

Sprint-1/implement/dedupe.test.js

@@ -16,13 +16,20 @@ 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.todo("given an empty array, it returns an empty array");
+test("given an empty array, returns 0", () => {
+    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 duplicate, returns original array", () => {
+    expect(dedupe([2,7,9])).toEqual([2,7,9]);
+});
 // 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 string or numbers, returns with no duplicates", () => {
+    expect(dedupe([4, "banana", 4, "banana", 2])).toEqual([4, "banana", 2]);
+});

Sprint-1/implement/max.js

@@ -1,4 +1,16 @@
 function findMax(elements) {
+    if (elements.length === 0){
+        return -Infinity;
+    }
+    let max = -Infinity;
+   for(let item of elements){
+    if(typeof item !== "number"){
+        continue;
+    }
+    if(item > max){
+        max = item;
+    }
+   }
+    return max;
 }
-
 module.exports = findMax;

Sprint-1/implement/max.test.js

@@ -16,28 +16,43 @@ 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([])).toBe(-Infinity);
+});
 
 // Given an array with one number
 // When passed to the max function
 // Then it should return that number
-
+test("given an empty array, returns 0", () => {
+    expect(findMax([78])).toBe(78);
+});
 // 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 positive and negative numbers, returns largest number", () => {
+    expect(findMax([-8, 10, 45, -60])).toBe(45);
+});
 // 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, returns closest to 0", () => {
+    expect(findMax([-8, -7, -5, -60])).toBe(-5);
+});
 // 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 largest number", () => {
+    expect(findMax([3.7, 5.8, 4.5, 60.8])).toBe(60.8);
+});
 // 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 number", () => {
+    expect(findMax([100, "hello", 94])).toBe(100);
+});
 // 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 non-numbers, returns -Infinity", () => {
+    expect(findMax(["hi", "maryam", "here"])).toBe(-Infinity);
+});

Sprint-1/implement/sum.js

@@ -1,4 +1,14 @@
 function sum(elements) {
-}
+    let result = 0;
+    if(elements.length === 0){
+        return 0;
+    }
+    for(let i = 0; i < elements.length; i++){
+        if(typeof(elements[i]) == "number"){
+            result = result + elements[i];
+        }
+    }
+    return result;
 
+}
 module.exports = sum;

Sprint-1/implement/sum.test.js

@@ -13,24 +13,39 @@ 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.todo("given an empty array, returns 0")
+
+test("given an empty array, returns 0", () => {
+    expect(sum([])).toBe(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 1 value, returns that value", () => {
+    expect(sum([50])).toBe(50);
+});
 // 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, returns correct sum", () => {
+    expect(sum([9, 2, 3, -4])).toBe(10);
+});
 // 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 correct sum", () => {
+    expect(sum([4.5, 9.2, 9, 3.2])).toBe(25.9);
+});
 // 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 containing non-number values, returns sum of only values", () => {
+    expect(sum([5, "banana", 2])).toBe(7);
+});
 // 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 with only non-number values, returns 0", () => {
+    expect(sum(["hi", "here"])).toBe(0);
+});

Sprint-1/refactor/includes.js

@@ -1,13 +1,10 @@
 // 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];
-    if (element === target) {
+  for(const element of list){
+    if(element === target ){
       return true;
     }
   }
   return false;
 }
-
-module.exports = includes;
+module.exports = includes;