Sheffield | May-2025 | Waleed- Salih-Taha | Sprint 2 | Data Group

Sprint-2/debug/address.js

@@ -1,4 +1,6 @@
 // Predict and explain first...
+// I think this code will log out "My house number is undefined"
+// because address[0] is trying to access an index that doesn't exist in the object.
 
 // This code should log out the houseNumber from the address object
 // but it isn't working...
@@ -12,4 +14,5 @@ const address = {
   postcode: "XYZ 123",
 };
 
-console.log(`My house number is ${address[0]}`);
+console.log(`My house number is ${address.houseNumber}`);
+// The code is already correct and will log the house number as expected.

Sprint-2/debug/author.js

@@ -1,8 +1,17 @@
 // Predict and explain first...
+// I think this code will not work as expected because the `for...of` 
+// loop is trying to iterate over an object.
+// Objects cannot be iterated directly with `for...of`.
 
 // 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
 
+//JavaScript objects like author aren’t directly iterable with a for...of loop.
+//for...of is designed to work with iterable objects like arrays, strings, maps, 
+// etc. Since author is a plain object, trying to iterate over it like that throws a TypeError.
+// To fix this, we can use `Object.values()` to get an array of the object's values
+//  and then iterate over that array.
+
 const author = {
   firstName: "Zadie",
   lastName: "Smith",
@@ -11,6 +20,8 @@ const author = {
   alive: true,
 };
 
-for (const value of author) {
+for (const value of Object.values(author)) {
   console.log(value);
 }
+// This code will now correctly log all the values of the author object.
+// The fix was to use Object.values(author) to get an array of the values

Sprint-2/debug/recipe.js

@@ -1,8 +1,13 @@
 // Predict and explain first...
+// I think this code will log out the title, how many it serves, and the ingredients.
+// However, it will not log each ingredient on a new line because the `recipe` object
 
 // 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?
+// The code is not correctly logging the ingredients on separate lines.
+// To fix this, we can use `join('\n')` on the ingredients array to format them correctly.
+// Additionally, we need to ensure that the template literal is formatted correctly.
 
 const recipe = {
   title: "bruschetta",
@@ -12,4 +17,5 @@ const recipe = {
 
 console.log(`${recipe.title} serves ${recipe.serves}
   ingredients:
-${recipe}`);
+${recipe.ingredients.join('\n')}`);
+// This code will now correctly log the title, number of servings, and each ingredient on a new line.

Sprint-2/implement/contains.js

@@ -1,3 +1,8 @@
-function contains() {}
+function contains(obj, key) {
+  if (typeof obj !== 'object' || obj === null || Array.isArray(obj)) {
+    return false;
+  }
+  return Object.hasOwn(obj, key);
+}
 
 module.exports = contains;

Sprint-2/implement/contains.test.js

@@ -17,19 +17,29 @@ as the object doesn't contains a key of 'c'
 // When passed an object and a property name
 // Then it should return true if the object contains the property, false otherwise
 
+
 // Given an empty object
 // When passed to contains
 // Then it should return false
-test.todo("contains on empty object returns false");
-
+test("contains on empty object returns false", () => {
+  expect(contains({}, 'a')).toBe(false);
+});
 // Given an object with properties
 // When passed to contains with an existing property name
 // Then it should return true
-
+test("contains on object with existing property returns true", () => {
+  expect(contains({ a: 1, b: 2 }, 'a')).toBe(true);
+});
 // Given an object with properties
 // When passed to contains with a non-existent property name
 // Then it should return false
+test("contains on object with non-existent property returns false", () => {
+  expect(contains({ a: 1, b: 2 }, 'c')).toBe(false);
+});
 
 // Given invalid parameters like an array
 // When passed to contains
 // Then it should return false or throw an error
+test("contains on array returns false", () => {
+  expect(contains([1, 2, 3], '1')).toBe(false);
+});

Sprint-2/implement/lookup.js

@@ -1,5 +1,17 @@
-function createLookup() {
+function createLookup(pairs) {
   // implementation here
+    if (!Array.isArray(pairs)) {
+    throw new Error("Input must be an array of [key, value] pairs");
+  }
+
+  return pairs.reduce((acc, pair) => {
+    if (!Array.isArray(pair) || pair.length !== 2) {
+      throw new Error("Each item must be an array with exactly 2 elements");
+    }
+    const [countryCode, currencyCode] = pair;
+    acc[countryCode] = currencyCode;
+    return acc;
+  }, {});
 }
 
 module.exports = createLookup;

Sprint-2/implement/lookup.test.js

@@ -1,7 +1,14 @@
 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 input = [['US', 'USD'], ['CA', 'CAD'], ['JP', 'JPY']];
+  const expected = {
+    US: 'USD',
+    CA: 'CAD',
+    JP: 'JPY'
+  };
+
+  expect(createLookup(input)).toEqual(expected);
+});
 /*
 
 Create a lookup object of key value pairs from an array of code pairs