LONDON | MAY 2025 | JESUS DEL MORAL | SPRINT 2 | DATA GROUPS

Sprint-2/debug/address.js

@@ -4,6 +4,10 @@
 // but it isn't working...
 // Fix anything that isn't working
 
+// When we use a Object and we want to extract any of the elements we don't refers them like a array [0] (position)
+// We can use the name of the object and follow the dot and the name of the element, with that we can extract the 
+// value of the element. 
+
 const address = {
   houseNumber: 42,
   street: "Imaginary Road",
@@ -12,4 +16,4 @@ 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

@@ -3,6 +3,9 @@
 // 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
 
+//To get all the values from a object we don't need go through using for loop 
+//We can use the function Object.values and in parenthesis the name of the Object 
+
 const author = {
   firstName: "Zadie",
   lastName: "Smith",
@@ -11,6 +14,7 @@ const author = {
   alive: true,
 };
 
-for (const value of author) {
-  console.log(value);
-}
+
+console.log(Object.values(author)); 
+
+

Sprint-2/debug/recipe.js

@@ -1,15 +1,19 @@
 // Predict and explain first...
 
+
 // 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?
 
+// To display in a new line each Ingredient I use  (.join("\n"))
+
 const recipe = {
   title: "bruschetta",
   serves: 2,
   ingredients: ["olive oil", "tomatoes", "salt", "pepper"],
 };
 
 console.log(`${recipe.title} serves ${recipe.serves}
-  ingredients:
-${recipe}`);
+ingredients:
+${recipe.ingredients.join("\n")}`);
+

Sprint-2/implement/contains.js

@@ -1,3 +1,11 @@
-function contains() {}
+function contains(input, containsvalues) {
+  if (!input || !containsvalues) {
+    return false;
+  }
+
+  return Object.values(input).includes(containsvalues);
+
+}
 
 module.exports = contains;
+

Sprint-2/implement/contains.test.js

@@ -1,15 +1,14 @@
 const contains = require("./contains.js");
 
-/*
-Implement a function called contains that checks an object contains a
-particular property
+//Implement a function called contains that checks an object contains a
+//particular property
 
-E.g. contains({a: 1, b: 2}, 'a') // returns true
-as the object contains a key of 'a'
+//E.g. contains({a: 1, b: 2}, 'a') // returns true
+//as the object contains a key of 'a'
 
-E.g. contains({a: 1, b: 2}, 'c') // returns false
-as the object doesn't contains a key of 'c'
-*/
+//E.g. contains({a: 1, b: 2}, 'c') // returns false
+//as the object doesn't contains a key of 'c'
+//*/
 
 // Acceptance criteria:
 
@@ -20,16 +19,72 @@ as the object doesn't contains a key of 'c'
 // Given an empty object
 // When passed to contains
 // Then it should return false
-test.todo("contains on empty object returns false");
+// test.todo("contains on empty object returns false");
+
+test("contains on empty object returns false", function () {
+
+    const input = "";
+    const currentOutput = contains(input);
+    const targetOutput = false;
+
+    expect(currentOutput).toEqual(targetOutput);
+});
+
 
 // Given an object with properties
 // When passed to contains with an existing property name
 // Then it should return true
 
+test("contains on with an existing property name", function () {
+
+  const input = {firstName: "Zaida", lastName: "Smith", occupation: "writer",age: 40,alive: true,};
+  const currentOutput = contains(input, "Zaida");
+  const targetOutput = true;
+
+  expect(currentOutput).toEqual(targetOutput);
+
+});
+
+
+
 // Given an object with properties
 // When passed to contains with a non-existent property name
 // Then it should return false
 
+test("contains returns false for non-existent property", function () {
+  const input = {
+    firstName: "Zaida",
+    lastName: "Smith",
+    occupation: "writer",
+    age: 40,
+    alive: true,
+  };
+
+  const currentOutput = contains(input, "middleName");
+  const targetOutput = false;
+
+  expect(currentOutput).toEqual(targetOutput);
+
+});
+
 // Given invalid parameters like an array
 // When passed to contains
 // Then it should return false or throw an error
+
+
+test("contains returns false for invalid parameter", function () {
+  const input = {
+    firstName: "Zaida",
+    lastName: "Smith",
+    occupation: "writer",
+    age: 40,
+    alive: true,
+  };
+
+  const currentOutput = contains(input, "errortest");
+  const targetOutput = false;
+
+  expect(currentOutput).toEqual(targetOutput);
+
+});
+

Sprint-2/implement/lookup.js

@@ -1,5 +1,18 @@
-function createLookup() {
-  // implementation here
+function createLookup(array) {
+  if (!array) {
+    return false;
+  }
+
+  const result = {};
+
+  for (let i = 0; i < array.length; i++) {
+    const [key, value] = array[i];
+    result [key] = value;
+  }
+
+  return result;
+
 }
 
 module.exports = createLookup;
+

Sprint-2/implement/lookup.test.js

@@ -1,6 +1,5 @@
 const createLookup = require("./lookup.js");
 
-test.todo("creates a country currency code lookup for multiple codes");
 
 /*
 
@@ -33,3 +32,13 @@ It should return:
    'CA': 'CAD'
  }
 */
+
+
+test("contains Array of arrays returns a object", function () {
+
+  const input = [['US', 'USD'], ['CA', 'CAD']];
+  const currentOutput = createLookup(input);
+  const targetOutput = {'US': 'USD', 'CA': 'CAD'};
+
+  expect(currentOutput).toEqual(targetOutput);
+});

Sprint-2/implement/querystring.js

@@ -1,12 +1,15 @@
 function parseQueryString(queryString) {
   const queryParams = {};
+
   if (queryString.length === 0) {
     return queryParams;
   }
+
   const keyValuePairs = queryString.split("&");
 
   for (const pair of keyValuePairs) {
-    const [key, value] = pair.split("=");
+    const [key, ...rest] = pair.split("=");
+    const value = rest.join("=");
     queryParams[key] = value;
   }
 

Sprint-2/implement/querystring.test.js

@@ -10,3 +10,28 @@ test("parses querystring values containing =", () => {
     "equation": "x=y+1",
   });
 });
+
+
+test("parses empty string", () => {
+  expect(parseQueryString("")).toEqual({});
+});
+
+test("parses single key=value", () => {
+  expect(parseQueryString("name=John")).toEqual({ name: "John" });
+});
+
+test("parses multiple key=value pairs", () => {
+  expect(parseQueryString("name=John&age=30")).toEqual({ name: "John", age: "30" });
+});
+
+test("handles missing value", () => {
+  expect(parseQueryString("name=")).toEqual({ name: "" });
+});
+
+test("handles missing key", () => {
+  expect(parseQueryString("=value")).toEqual({ "": "value" });
+});
+
+test("handles duplicate keys (last one wins)", () => {
+  expect(parseQueryString("name=John&name=Jane")).toEqual({ name: "Jane" });
+});

Sprint-2/implement/tally.js

@@ -1,3 +1,27 @@
-function tally() {}
+// It loops over each item in the array.
+
+// If the item is already in the counts object, it increments the count.
+
+// If not, it initializes it with 1.
+
+function tally(items) {
+    if (!Array.isArray(items)) {
+      throw new Error("Input must be an array");
+    }
+
+    const counts = {};
+
+    for (const item of items) {
+      counts[item] = (counts[item] || 0) + 1;
+    }
+
+    return counts;
+  }
+
+
 
 module.exports = tally;
+
+
+
+

Sprint-2/implement/tally.test.js

@@ -19,16 +19,31 @@ const tally = require("./tally.js");
 // Given a function called tally
 // When passed an array of items
 // Then it should return an object containing the count for each unique item
+test("parse an array, return an object containing the count for each unique item", () => {
+    expect(tally(['a', 'a', 'a'])).toEqual({ a: 3});
+  });
 
 // Given an empty array
 // When passed to tally
 // Then it should return an empty object
-test.todo("tally on an empty array returns an empty object");
+test("Given an empty array, return an empty object", () => {
+    expect(tally([])).toEqual({});
+  });
+
+
 
 // Given an array with duplicate items
 // When passed to tally
 // Then it should return counts for each unique item
+test("parse an array, return an object containing the count for each unique item", () => {
+    expect(tally(['a', 'b', 'b', 'a', 'a', 'c'])).toEqual({ a: 3, b: 2, c:1});
+  });
 
 // Given an invalid input like a string
 // When passed to tally
 // Then it should throw an error
+test("Given an invalid input like a string, it should throw an error", () => {
+    expect(() => tally("not an array")).toThrow("Input must be an array");
+  });
+
+

Sprint-2/interpret/invert.js

@@ -10,20 +10,43 @@ function invert(obj) {
   const invertedObj = {};
 
   for (const [key, value] of Object.entries(obj)) {
-    invertedObj.key = value;
+    invertedObj[value] = key;
   }
 
   return invertedObj;
 }
 
 // a) What is the current return value when invert is called with { a : 1 }
 
+// Return { key: 1 }
+
 // b) What is the current return value when invert is called with { a: 1, b: 2 }
 
+// Return { key: 2 }
+
 // c) What is the target return value when invert is called with {a : 1, b: 2}
 
+// Target return {"1": "a", "2": "b"}
+
 // c) What does Object.entries return? Why is it needed in this program?
 
+// It returns an array of key–value pairs from the object. Using Object.entries(obj) gives us both the key and value in each iteration:
+
 // d) Explain why the current return value is different from the target output
 
+// The reason is this line  (invertedObj.key = value;), dot notation with a literal property name "key", not the variable key.
+
+
 // e) Fix the implementation of invert (and write tests to prove it's fixed!)
+
+
+/* function invert(obj) {
+  const invertedObj = {};
+
+  for (const [key, value] of Object.entries(obj)) {
+    invertedObj[value] = key;
+  }
+
+  return invertedObj;
+}
+*/

Sprint-2/stretch/count-words.js

@@ -26,3 +26,20 @@
 
 3. Order the results to find out which word is the most common in the input
 */
+
+function countWords(querystring) {
+  const wordCounts = {};
+
+ // Remove punctuation and convert to lowercase for consistency
+ const cleanedStr = str.replace(/[.,!?]/g, "").toLowerCase();
+
+ const words = cleanedStr.split(" ");
+
+ for (const word of words) {
+   if (word === "") continue; // skip empty strings from multiple spaces
+   wordCounts[word] = (wordCounts[word] || 0) + 1;
+ }
+
+ return wordCounts;
+
+}