London | 26-ITP-May | el | Sprint 2 | interpret

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);
+});

Sprint-1/refactor/includes.js

@@ -1,8 +1,7 @@
 // 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;
     }

Sprint-2/debug/address.js

@@ -1,5 +1,5 @@
 // Predict and explain first...
-
+// i think its because the address is not used as an array but as an object
 // This code should log out the houseNumber from the address object
 // but it isn't working...
 // Fix anything that isn't working
@@ -12,4 +12,4 @@ const address = {
   postcode: "XYZ 123",
 };
 
-console.log(`My house number is ${address[0]}`);
+console.log(`My house number is ${address.houseNumber}`);

Sprint-2/debug/author.js

@@ -1,8 +1,8 @@
 // Predict and explain first...
-
+//i think its because value is not used as a parameter of an object, and author is an object not an ordered list Array.
 // This program attempts to log out all the property values in the object.
 // But it isn't working. Explain why first and then fix the problem
-
+// i found that object literals are not iterative because they have no orders
 const author = {
   firstName: "Zadie",
   lastName: "Smith",
@@ -11,6 +11,6 @@ const author = {
   alive: true,
 };
 
-for (const value of author) {
+for (const value of Object.values(author)) {
   console.log(value);
 }

Sprint-2/debug/recipe.js

@@ -1,5 +1,9 @@
 // Predict and explain first...
-
+/*
+console.log(`${recipe.title} serves ${recipe.serves}
+  ingredients:
+${recipe}`);// here it misses recipe.ingredients 
+  */
 // This program should log out the title, how many it serves and the ingredients.
 // Each ingredient should be logged on a new line
 // How can you fix it?
@@ -12,4 +16,4 @@ const recipe = {
 
 console.log(`${recipe.title} serves ${recipe.serves}
   ingredients:
-${recipe}`);
+${recipe.ingredients.join("\n")}`); // this make the list to be logged on a new line - not predicted at first

Sprint-2/interpret/invert.js

@@ -10,20 +10,36 @@ function invert(obj) {
   const invertedObj = {};
 
   for (const [key, value] of Object.entries(obj)) {
-    invertedObj.key = value;
+    //invertedObj.key = value;
+    invertedObj[value] = key;
   }
 
   return invertedObj;
 }
+/*
+console.log(invert({ a: 1 })); // {1:a}
+console.log(invert({ a: 1, b: 2 }));
+console.log(invert({ a: 1, b: 2 }));
+*/
 
 // a) What is the current return value when invert is called with { a : 1 }
-
+/*
+    {
+  key: 1;
+}
+  */
 // b) What is the current return value when invert is called with { a: 1, b: 2 }
-
+/*
+    {
+  key: 2;
+}
+  */
 // c) What is the target return value when invert is called with {a : 1, b: 2}
-
+// {"1":"a", "2":"b"}
 // c) What does Object.entries return? Why is it needed in this program?
-
+//object.entries takes an objecet and returns an array of its key-value pairs.
 // d) Explain why the current return value is different from the target output
-
+//because we use .key notation we are setting a property named "key" on our Object.
 // e) Fix the implementation of invert (and write tests to prove it's fixed!)
+
+module.exports = invert;

Sprint-2/interpret/invert.test.js

@@ -0,0 +1,8 @@
+const invert = require("./invert.js");
+test("invert the key and values", () => {
+  expect(invert({ a: 1 })).toEqual({ 1: "a" });
+});
+
+test("invert the key and values", () => {
+  expect(invert({ a: 1, b: 2 })).toEqual({ 1: "a", 2: b });
+});