From 4ee9bf8efd19993b53f06617761a81af933febf6 Mon Sep 17 00:00:00 2001 From: Richard Frimpong Date: Fri, 13 Mar 2026 21:22:28 +0000 Subject: [PATCH] Implement sprint 1 array exercises --- Sprint-1/implement/dedupe.js | 18 +++++++++++++++++- Sprint-1/implement/dedupe.test.js | 20 ++++++++++++++++++-- Sprint-1/implement/max.js | 15 +++++++++++++++ Sprint-1/implement/max.test.js | 23 +++++++++++++++++++++-- Sprint-1/implement/sum.js | 13 +++++++++++++ Sprint-1/implement/sum.test.js | 19 ++++++++++++++++++- 6 files changed, 102 insertions(+), 6 deletions(-) diff --git a/Sprint-1/implement/dedupe.js b/Sprint-1/implement/dedupe.js index 781e8718a..f8494b4a5 100644 --- a/Sprint-1/implement/dedupe.js +++ b/Sprint-1/implement/dedupe.js @@ -1 +1,17 @@ -function dedupe() {} +// Return a new array with duplicate values removed. +// Keep the first occurrence of each value. + +function dedupe(elements) { + const uniqueElements = []; + + for (const element of elements) { + // Add the element only if it is not already in the result array + if (!uniqueElements.includes(element)) { + uniqueElements.push(element); + } + } + + return uniqueElements; +} + +module.exports = dedupe; diff --git a/Sprint-1/implement/dedupe.test.js b/Sprint-1/implement/dedupe.test.js index 23e0f8638..0360f8e81 100644 --- a/Sprint-1/implement/dedupe.test.js +++ b/Sprint-1/implement/dedupe.test.js @@ -2,7 +2,7 @@ const dedupe = require("./dedupe.js"); /* Dedupe Array -📖 Dedupe means **deduplicate** +📖 Dedupe means deduplicate In this kata, you will need to deduplicate the elements of an array @@ -16,12 +16,28 @@ E.g. dedupe([1, 2, 1]) target output: [1, 2] // 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("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 the same values", () => { + expect(dedupe([1, 2, 3])).toEqual([1, 2, 3]); +}); // 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 duplicate strings, removes duplicates and preserves first occurrence", () => { + expect(dedupe(["a", "a", "a", "b", "b", "c"])).toEqual(["a", "b", "c"]); +}); + +test("given an array with duplicate numbers, removes duplicates and preserves first occurrence", () => { + expect(dedupe([5, 1, 1, 2, 3, 2, 5, 8])).toEqual([5, 1, 2, 3, 8]); +}); + +test("given a mixed duplicate order, removes duplicates and preserves first occurrence", () => { + expect(dedupe([1, 2, 1])).toEqual([1, 2]); +}); diff --git a/Sprint-1/implement/max.js b/Sprint-1/implement/max.js index 6dd76378e..df7d3f86b 100644 --- a/Sprint-1/implement/max.js +++ b/Sprint-1/implement/max.js @@ -1,4 +1,19 @@ +// Find the largest numerical value in an array. +// Non-number values should be ignored. + function findMax(elements) { + let maxValue = -Infinity; + + for (const element of elements) { + // Only compare values that are real numbers + if (typeof element === "number" && !Number.isNaN(element)) { + if (element > maxValue) { + maxValue = element; + } + } + } + + return maxValue; } module.exports = findMax; diff --git a/Sprint-1/implement/max.test.js b/Sprint-1/implement/max.test.js index 82f18fd88..95f92f165 100644 --- a/Sprint-1/implement/max.test.js +++ b/Sprint-1/implement/max.test.js @@ -15,29 +15,48 @@ const findMax = require("./max.js"); // Given an empty array // 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([42])).toBe(42); +}); // 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", () => { + expect(findMax([-10, 3, 25, -1])).toBe(25); +}); // 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 only negative numbers, returns the largest one", () => { + expect(findMax([-9, -2, -15, -4])).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", () => { + expect(findMax([1.2, 3.8, 2.4])).toBe(3.8); +}); // 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, ignores them and returns the max", () => { + expect(findMax(["hey", 10, "hi", 60, 10])).toBe(60); +}); // 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(["apple", null, undefined, "banana"])).toBe(-Infinity); +}); diff --git a/Sprint-1/implement/sum.js b/Sprint-1/implement/sum.js index 9062aafe3..1a0c9ddb3 100644 --- a/Sprint-1/implement/sum.js +++ b/Sprint-1/implement/sum.js @@ -1,4 +1,17 @@ +// Sum the numerical values in an array. +// Non-number values should be ignored. + function sum(elements) { + let total = 0; + + for (const element of elements) { + // Only add values that are real numbers + if (typeof element === "number" && !Number.isNaN(element)) { + total += element; + } + } + + return total; } module.exports = sum; diff --git a/Sprint-1/implement/sum.test.js b/Sprint-1/implement/sum.test.js index dd0a090ca..67e440741 100644 --- a/Sprint-1/implement/sum.test.js +++ b/Sprint-1/implement/sum.test.js @@ -13,24 +13,41 @@ 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 one number, returns that number", () => { + expect(sum([7])).toBe(7); +}); // 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 with negative numbers, returns the correct sum", () => { + expect(sum([-5, 10, -2])).toBe(3); +}); // 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 numbers, returns the correct sum", () => { + expect(sum([1.5, 2.5, 3])).toBe(7); +}); // 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 with non-number values, ignores them and sums only numbers", () => { + expect(sum(["hey", 10, "hi", 60, 10])).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(["apple", null, undefined, "banana"])).toBe(0); +});