London | 26-ITP-Jan | Mohsen Zamani | sprint 2 | coursework by mohsenzamanist · Pull Request #953 · CodeYourFuture/Module-Data-Groups

mohsenzamanist · 2026-02-10T23:39:14Z

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I have titled my PR with Region | Cohort | FirstName LastName | Sprint | Assignment Title
My changes meet the requirements of the task
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Complete Sprint 2 exercises.

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Sprint-2/debug/recipe.js

Sprint-2/implement/contains.js

Sprint-2/implement/contains.test.js

cjyuan · 2026-02-20T13:11:25Z

Sprint-2/implement/contains.test.js

+  expect(() => contains(undefined, "key1")).toThrow(
+    "The parameter given is not a plain JS object."
+  );
+  expect(() => contains(null, "key1")).toThrow(
+    "The parameter given is not a plain JS object."
+  );


Number is not a plain JS object but it is given a different treatment.

Wouldn't it be "friendlier to the caller" if the function can be designed to behave consistently for any value that is not an object or is an array?

Sprint-2/implement/contains.test.js

Sprint-2/implement/querystring.js

Sprint-2/implement/tally.js

Sprint-2/interpret/invert.js

cjyuan · 2026-02-20T13:29:11Z

Sprint-2/stretch/count-words.js

+function countWords(string) {
+  const noPunctuationStr = string.replace(/[.,!?]/g, "");
+  const wordArray = noPunctuationStr.split(" ");
+  let wordCount = new Map();
+  for (let word of wordArray) {
+    wordCount.set(word, (wordCount.get(word) || 0) + 1);
+  }
+  const sortedWordCount = [...wordCount.entries()].sort((a, b) => b[1] - a[1]);
+  return sortedWordCount;


Can you check if your function returns what you expect in the following function calls?

countWords("Hello,World! Hello World!"); countWords(" Hello World ");

cjyuan · 2026-02-23T17:57:17Z

Sprint-2/implement/contains.js

@@ -1,3 +1,9 @@
-function contains() {}
+function contains(obj, property) {
+  if (Object.prototype.toString.call(obj) !== "[object Object]") return false;


This approach to check if obj is an object is not 100% accurate. For example,

const map = new Map() console.log(map instanceof Object); // true console.log(Object.prototype.toString.call(map)) // [object Map]

map is an object but your approach would not recognise it as an object.

This test description in contains.test.js is a bit vague because an array is a kind of object in JavaScript:

// Given invalid parameters like an array
// When passed to contains
// Then it should return false or throw an error

Can you interpret "invalid parameter" as "it is not an object OR it is an array"?

Does the code only need to check the plain objects (excluding Map)?

I do not know the intent of the person who wrote the test description. My interpretation is, accept all objects except arrays.

The approach you were using is not a reliable way to check for pure Object. Without a more specific description of what is expected of such object, let's just practice on "accept any object that is not an array"

cjyuan · 2026-02-23T18:10:12Z

Sprint-2/stretch/count-words.js

+  const sortedWordCount = new Map([...wordCount].sort(([, a], [, b]) => b - a));
+  return sortedWordCount;


The syntax of the expected output on line 13 seems to suggest the return value should be a plain JS object instead of a Map object.

On line 39, it would make the statement more readable if a and b are replaced by more meaningful identifiers.

cjyuan

Could you remove the debugging code to keep the code clean?

cjyuan · 2026-02-23T20:28:05Z

Sprint-2/stretch/count-words.js

    .split(/[.,!? ]+/)
    .filter(Boolean);
-  let wordCount = new Map();
+  const wordCount = {};


Note: You could just change the code on line 39 and keep wordCount as a Map object.

cjyuan · 2026-02-23T20:28:59Z

Sprint-2/implement/contains.js

-  if (Object.prototype.toString.call(obj) !== "[object Object]") return false;
-
+  if (Array.isArray(obj) || obj === null || typeof obj !== "object") {
+    console.log("here");


Debugging code should be removed to make the code cleaner.

complete feature/sprint-2

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		const sortedWordCount = new Map([...wordCount].sort(([, a], [, b]) => b - a));
		return sortedWordCount;

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mohsenzamanist commented Feb 10, 2026

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