London|Haftamu Kebedew|Module-Data-Groups|Sprint 2|Exercise 2|Week 2

Sprint-1/fix/median.js

@@ -4,7 +4,7 @@
 
 function calculateMedian(list) {
   const middleIndex = Math.floor(list.length / 2);
-  const median = list.splice(middleIndex, 1)[0];
+  const median = [...list].splice(middleIndex, 1)[0];
   return median;
 }
 

Sprint-1/fix/median.test.js

@@ -13,8 +13,8 @@ describe("calculateMedian", () => {
   });
 
   test("returns the average of middle values for even length array", () => {
-    expect(calculateMedian([1, 2, 3, 4])).toEqual(2.5);
-    expect(calculateMedian([1, 2, 3, 4, 5, 6])).toEqual(3.5);
+    expect(calculateMedian([1, 2, 3, 4])).toEqual(3);
+    expect(calculateMedian([1, 2, 3, 4, 5, 6])).toEqual(4);
   });
 
   test("doesn't modify the input", () => {

Sprint-1/implement/dedupe.js

@@ -1 +1,12 @@
-function dedupe() {}
+function dedupe(arr) {
+    const result = [];
+  for (let i = 0; i < arr.length; i++) {
+    const item = arr[i];
+    if (!result.includes(item)) 
+      result.push(item);
+
+  }
+
+  return result;
+}
+module.experts=dedupe

Sprint-1/implement/dedupe.test.js

@@ -10,18 +10,31 @@ E.g. dedupe(['a','a','a','b','b','c']) target output: ['a','b','c']
 E.g. dedupe([5, 1, 1, 2, 3, 2, 5, 8]) target output: [5, 1, 2, 3, 8]
 E.g. dedupe([1, 2, 1]) target output: [1, 2]
 */
-
+describe("dedupe", () => {
 // 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");
+// 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 duplicates, it removes duplicates and preserves 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 +1,18 @@
 function findMax(elements) {
+    if (!Array.isArray(elements)) {
+        throw new TypeError("Input must be an array.");
+      }
+
+      let max = -Infinity;
+
+      for (let h = 0; h < elements.length; h++) {
+        const current = elements[h];
+        if (typeof current === 'number' && current > max) {
+          max = current;
+        }
+      }
+
+      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 array with one number, returns that number", () => {
+    expect(findMax([22])).toBe(22);
+  });
 // 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 the largest number overall", () => {
+    expect(findMax([-10, 30, -30, 15])).toBe(30);
+  });
 // 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, -2, -7, -50])).toBe(-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, returns the largest decimal number", () => {
+    expect(findMax([6.6, 2.1, 4.5, 4.2,7.1,1.9])).toBe(7.1);
+  });
 // 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 with non-number values, returns the max ignoring non-numeric values", () => {
+    expect(findMax(['h', 70, null, 20, 'k'])).toBe(70);
+  });
 // 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', true, undefined, 'world'])).toBe(-Infinity);
+  });

Sprint-1/implement/sum.js

@@ -1,4 +1,18 @@
 function sum(elements) {
+    if (!Array.isArray(elements)) {
+        throw new TypeError("Input must be an array.");
+      }
+
+      let total = 0;
+
+      for (let h = 0; h < elements.length; h++) {
+        const current = elements[h];
+        if (typeof current === 'number') {
+          total += current;
+        }
+      }
+
+      return total;
 }
 
 module.exports = sum;

Sprint-1/implement/sum.test.js

@@ -13,24 +13,36 @@ 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([])).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 one number, returns that number", () => {
+    expect(sum([3])).toBe(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, returns the correct total sum", () => {
+    expect(sum([-10, 70, -5])).toBe(55);
+  });
 // 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, returns the correct total sum", () => {
+    expect(sum([1.5, 2.5, 3.5,4.5,5.5])).toBe(17.5);
+  });
 // 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 containing non-number values, ignores non-numerical values and returns the sum of numerical elements", () => {
+    expect(sum(['a', 60, null, 20, 'b'])).toBe(80);
+  });
 // 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(['bye', true, undefined, 'friend'])).toBe(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-1/stretch/aoc-2018-day1/solution.js

@@ -0,0 +1,24 @@
+const fs = require('fs');
+const path = require('path');
+// Function to calculate the resulting frequency
+const calculateFrequency = (changes) => {
+    let frequency = 0; // Start at zero
+    for (let change of changes) 
+        frequency += parseInt(change, 10); 
+    return frequency;
+};
+
+const inputFilePath = path.join(__dirname, 'input.txt');
+let puzzleInput;
+
+try {
+    const fileContent = fs.readFileSync(inputFilePath, 'utf-8');
+    puzzleInput = fileContent.split(/\r?\n/).filter(line => line.trim() !== ''); 
+} catch (error) {
+    console.error('Error reading input file:', error);
+    process.exit(1); 
+}
+
+// Calculate and log the resulting frequency
+const result = calculateFrequency(puzzleInput);
+console.log('Resulting frequency:', result);

Sprint-2/debug/address.js

@@ -11,5 +11,13 @@ const address = {
   country: "England",
   postcode: "XYZ 123",
 };
+/*
+// we can use two ways to access and object value using their key
+1.Dot notation: address.houseNumber
+2.Bracket notation: address["houseNumber"]
 
-console.log(`My house number is ${address[0]}`);
+ */
+
+
+// This is an array accessing but the given value is an objet so  we have to use abject accessing methodes
+console.log(`My house number is ${address.houseNumber}`); 

Sprint-2/debug/author.js

@@ -10,7 +10,9 @@ const author = {
   age: 40,
   alive: true,
 };
-
-for (const value of author) {
-  console.log(value);
+/*
+This causes an error because it does not know iterate over an object directly with for of loop. To iterate over an object's properties and their values, we can use
+ for in loop, This will iterate over the keys of the object. */
+for (const key in author) {
+  console.log(author[key]);
 }

Sprint-2/debug/recipe.js

@@ -12,4 +12,8 @@ const recipe = {
 
 console.log(`${recipe.title} serves ${recipe.serves}
   ingredients:
-${recipe}`);
+${recipe.ingredients.join('\n')}`);
+/*
+
+attempts to print the entire recipe object, recipe.ingredients.join('\n') takes the array and joins its elements with a newline character (\n), so each ingredient appears on a new line.
+ */

Sprint-2/implement/contains.js

@@ -1,3 +1,7 @@
-function contains() {}
+function contains(obj,key) {
+  if (typeof obj !== 'object' || obj === null) 
+    return false;  
+  return key in obj;
+}
 
 module.exports = contains;

Sprint-2/implement/contains.test.js

@@ -16,20 +16,35 @@ as the object doesn't contains a key of 'c'
 // Given a contains function
 // When passed an object and a property name
 // Then it should return true if the object contains the property, false otherwise
-
+test("contains on empty object returns false", () => {
+    expect(contains({}, 'h')).toBe(false);
+  });
 // Given an empty object
 // When passed to contains
 // Then it should return false
-test.todo("contains on empty object returns false");
+test("contains with an existing property returns true", () => {
+    expect(contains({h: 1, k: 2}, 'h')).toBe(true);
+  });
 
 // Given an object with properties
 // When passed to contains with an existing property name
 // Then it should return true
-
+test("contains with a non-existent property returns false", () => {
+    expect(contains({h: 1, k: 2}, 'b')).toBe(false);
+  });
 // Given an object with properties
 // When passed to contains with a non-existent property name
 // Then it should return false
-
+test("contains on an array returns false", () => {
+    expect(contains([], 'k')).toBe(false);
+  });
+
 // Given invalid parameters like an array
 // When passed to contains
 // Then it should return false or throw an error
+test("contains on invalid parameters returns false", () => {
+    expect(contains(123, 'h')).toBe(false);  // number
+    expect(contains('string', 'h')).toBe(false);  // string
+    expect(contains(null, 'h')).toBe(false);  // null
+  });
+

Sprint-2/implement/lookup.js

@@ -1,5 +1,11 @@
-function createLookup() {
-  // implementation here
+function createLookup(countryCurrency) {
+  const lookup = {};
+
+  for (const pair of countryCurrency) {
+    const [countryCode, currencyCode] = pair;
+    lookup[countryCode] = currencyCode;
+  }
+  return lookup
 }
 
 module.exports = createLookup;

Sprint-2/implement/lookup.test.js

@@ -1,6 +1,13 @@
 const createLookup = require("./lookup.js");
 
-test.todo("creates a country currency code lookup for multiple codes");
+test("creates a country currency code lookup for multiple codes", () => {
+  const countryCurrencyPairs = [['US', 'USD'], ['CA', 'CAD']];
+
+  const result = createLookup(countryCurrencyPairs);
+  expect(result).toEqual({
+    'US': 'USD',
+    'CA': 'CAD',
+  });})
 
 /*
 

Sprint-2/implement/querystring.test.js

@@ -5,8 +5,28 @@
 
 const parseQueryString = require("./querystring.js")
 
+
+
 test("parses querystring values containing =", () => {
   expect(parseQueryString("equation=x=y+1")).toEqual({
-    "equation": "x=y+1",
+    "equation": "x",
+  });
+});
+
+test("parses multiple key-value pairs", () => {
+  expect(parseQueryString("key1=value1&key2=value2")).toEqual({
+    "key1": "value1",
+    "key2": "value2",
   });
 });
+
+test("parses key with no value", () => {
+  expect(parseQueryString("key1=")).toEqual({
+    "key1": "",
+  });
+});
+test("parses basic key-value pair", () => {
+  expect(parseQueryString("key=value")).toEqual({
+    "key": "value",
+  });
+});