Birmingham | ITP-Jan-26 | Ayodeji Ayorinde | Sprint 2| Coursework/Sprint2

Sprint-2/debug/address.js

@@ -1,4 +1,4 @@
-// Predict and explain first...
+// Predict and explain first...It should report the house number as 42
 
 // This code should log out the houseNumber from the address object
 // but it isn't working...
@@ -12,4 +12,6 @@ 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

@@ -1,4 +1,4 @@
-// Predict and explain first...
+// Predict and explain first...It should report 40 as the value
 
 // 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
@@ -11,6 +11,7 @@ const author = {
   alive: true,
 };
 
-for (const value of author) {
+//for (const value of author) {
+for (const value of Object.values(author)) {
   console.log(value);
 }

Sprint-2/debug/recipe.js

@@ -1,4 +1,4 @@
-// Predict and explain first...
+// Predict and explain first...It should report the title, serves & ingredient but ingredient might have issues.
 
 // This program should log out the title, how many it serves and the ingredients.
 // Each ingredient should be logged on a new line
@@ -10,6 +10,11 @@ const recipe = {
   ingredients: ["olive oil", "tomatoes", "salt", "pepper"],
 };
 
-console.log(`${recipe.title} serves ${recipe.serves}
-  ingredients:
-${recipe}`);
+// 1. Log the title and servings
+console.log(`${recipe.title} serves ${recipe.serves}`);
+console.log("Ingredients:");
+
+// 2. Loop through ingredients to log each on a new line
+recipe.ingredients.forEach(ingredient => {
+  console.log(`- ${ingredient}`);
+});

Sprint-2/implement/contains.js

@@ -1,3 +1,19 @@
+/*
 function contains() {}
 
 module.exports = contains;
+*/
+
+function contains(obj, propName) {
+    if (
+        typeof obj !== 'object' ||
+        obj === null ||
+        (typeof propName !== 'string' && typeof propName !== 'number' && typeof propName !== 'symbol')
+    ) {
+        return false;
+    }
+    return propName in obj;
+}
+
+module.exports = contains;
+

Sprint-2/implement/lookup.js

@@ -1,5 +1,7 @@
-function createLookup() {
-  // implementation here
-}
+
+const createLookup = (countryCurrencyPairs) => {
+  return Object.fromEntries(countryCurrencyPairs);
+};
+
 
 module.exports = createLookup;

Sprint-2/implement/querystring.js

@@ -1,3 +1,4 @@
+/*
 function parseQueryString(queryString) {
   const queryParams = {};
   if (queryString.length === 0) {
@@ -12,5 +13,43 @@ function parseQueryString(queryString) {
 
   return queryParams;
 }
+  */
+
+
+
+
+
+
+function parseQueryString(queryString) {
+  if (!queryString || queryString.trim() === "") {
+    return {};
+  }
+
+  const cleanedString = queryString.startsWith("?") // check if it has ? and remocve
+    ? queryString.substring(1)
+    : queryString;
+
+  const pairs = cleanedString.split("&"); //Split
+  const result = {};
+
+  for (const pair of pairs) {
+    // split on the FIRST '='
+    const [key, ...valueParts] = pair.split("=");
+    const value = valueParts.join("="); // Rejoin if value contained '='
+
+    // Decode key and value to handle special characters
+    const decodedKey = decodeURIComponent(key);
+    const decodedValue = value ? decodeURIComponent(value) : "";
+
+    if (decodedKey) {
+      result[decodedKey] = decodedValue;
+    }
+  }
+
+  return result;
+
+}
+
+
 
 module.exports = parseQueryString;

Sprint-2/implement/tally.js

@@ -1,3 +1,18 @@
-function tally() {}
+
+
+function tally(arr) {
+    // Input validation
+
+    if (!Array.isArray(arr)) {
+        throw new Error("Input must be an array");
+    }
+
+    // The reduction method effectively builds the frequency map
+    return arr.reduce((acc, item) => {
+        acc[item] = (acc[item] || 0) + 1;
+        return acc;
+    }, {});
+}
+
 
 module.exports = tally;

Sprint-2/interpret/invert.js

@@ -6,6 +6,7 @@
 
 // E.g. invert({x : 10, y : 20}), target output: {"10": "x", "20": "y"}
 
+
 function invert(obj) {
   const invertedObj = {};
 
@@ -16,14 +17,38 @@ function invert(obj) {
   return invertedObj;
 }
 
-// a) What is the current return value when invert is called with { a : 1 }
+console.log(invert({ a: 1, b: 2 }));
+
+
+// a) What is the current return value when invert is called with { a : 1 }. ANSWER =  { key: 1 }
 
-// b) What is the current return value when invert is called with { a: 1, b: 2 }
+// b) What is the current return value when invert is called with { a: 1, b: 2 }. ANSWER = { key: 2 }
 
-// c) What is the target return value when invert is called with {a : 1, b: 2}
+// c) What is the target return value when invert is called with {a : 1, b: 2}. ANSWER = { "1": "a", "2": "b" }
 
 // c) What does Object.entries return? Why is it needed in this program?
+//ANSWER:
+// c(i)  Object.entries(obj) returns an array of [key, value] pairs e.g ({ a: 1, b: 2 }) → [["a", 1], ["b", 2]]
+// c(ii) Object.entries allows you to loop through both keys and values .
 
 // d) Explain why the current return value is different from the target output
+//ANSWER: It is different because the line is assigning to the literal property "key" instead of using the variable key or value
 
 // 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;
+}
+
+
+
+console.log(invert({ a: 1 }))
+console.log(invert({ a: 1, b: 2 }))
+
+