Initial commit.

.gitattributes

+# Disable line-ending conversions for this repository.
+* -text

.gitignore

+# dependencies
+/node_modules
+
+# testing
+/coverage
+
+# production
+/build
+
+# environments
+.env.local
+.env.development.local
+.env.test.local
+.env.production.local
+
+# logs
+npm-debug.log*
+yarn-debug.log*
+yarn-error.log*
+
+# misc
+*~
+.DS_Store

.gitmodules

+[submodule "eslint-config"]
+	path = eslint-config
+	url = git@git.unl.edu:soft-core/soft-260/eslint-config.git

README.md

+# JavaScript Practice
+
+A collection of small JavaScript exercises for practice when learning the
+language.
+
+# Quick Start
+
+Recursively clone this repository and `cd` into the root folder:
+
+```
+$ git clone --recursive git@git.unl.edu:soft-core/soft-260/javascript-practice.git
+$ cd javascript-practice
+```
+
+(If you forget `--recursive` when cloning, you can `cd` into your clone and run
+`git submodule update --init --recursive` instead.)
+
+Install dependencies:
+
+```
+$ npm install
+```
+
+Optionally run the linter and the test suite:
+
+```
+$ npm run lint
+$ npm run test
+```
+
+# Exercises
+
+In the `src` folder there are 19 folders lettered `a` to `s`, each named for
+some feature of the JavaScript language and containing an exercise on using that
+feature.  Within each folder are three files:
+
+*   An ordinary `*.js` file.  This file will contain a small piece of starter
+    code and comments with instructions on what code to write where the comment
+    appears.  You can edit this file to solve the exercise.
+
+*   A `*.key.js` file.  This file contains a solution to the exercise in case
+    you get stuck.
+
+*   A `*.test.js` file.  This file contains test cases to check your solution.
+    In case the instructions are unclear, you can also read these test cases to
+    better understand what the code under test should do.
+
+Once you have attempted an exercise, you can save your changes to the `*.js`
+file and then test your work with a command like
+
+```
+$ npm run test-once:a
+```
+
+where the letter after the colon is the letter of the exercise.  These test
+scripts are also available from the "NPM SCRIPTS" tray in VSCode.
+
+To check your code style, use the command
+
+```
+$ npm run lint
+```
+
+Or run the `lint` task from the "NPM SCRIPTS" tray in VSCode.  Note that the
+linter may report some style errors for exercises that you have yet to complete.

eslint-config @ a85278e2

+Subproject commit a85278e2bd62f637800bc32fa6b372bc2855546e

javascript-practice.code-workspace

+{
+	"folders": [
+		{
+			"path": "."
+		}
+	],
+	"settings": {
+		"files.eol": "LF",
+		"files.exclude": {
+			"**/node_modules": true
+		},
+		"files.trimFinalNewlines": true,
+		"files.trimTrailingWhitespace": true
+	}
+}

javascript-practice/.gitignore

+# dependencies
+/node_modules
+
+# testing
+/coverage
+
+# production
+/build
+
+# environments
+.env.local
+.env.development.local
+.env.test.local
+.env.production.local
+
+# logs
+npm-debug.log*
+yarn-debug.log*
+yarn-error.log*
+
+# misc
+*~
+.DS_Store

javascript-practice/package.json

+{
+  "name": "@unlsoft/javascript-practice",
+  "version": "1.0.0",
+  "description": "A collection of small JavaScript exercises for practice when learning the language.",
+  "type": "module",
+  "private": true,
+  "license": "UNLICENSED",
+  "scripts": {
+    "lint:js": "eslint --max-warnings 0 ./src",
+    "lint": "run-s --continue-on-error lint:**",
+    "test-once:a": "node --experimental-vm-modules node_modules/jest/bin/jest.js -t \"\\`formatAsTriple\\` function\"",
+    "test-once:b": "node --experimental-vm-modules node_modules/jest/bin/jest.js -t \"\\`classify\\` function\"",
+    "test-once:c": "node --experimental-vm-modules node_modules/jest/bin/jest.js -t \"\\`decodeCountingNumber\\` function\"",
+    "test-once:d": "node --experimental-vm-modules node_modules/jest/bin/jest.js -t \"\\`countDigits\\` function\"",
+    "test-once:e": "node --experimental-vm-modules node_modules/jest/bin/jest.js -t \"\\`triangularNumber\\` function\"",
+    "test-once:f": "node --experimental-vm-modules node_modules/jest/bin/jest.js -t \"\\`sum\\` function\"",
+    "test-once:g": "node --experimental-vm-modules node_modules/jest/bin/jest.js -t \"first \\`Book\\` class\"",
+    "test-once:h": "node --experimental-vm-modules node_modules/jest/bin/jest.js -t \"second \\`Book\\` class\"",
+    "test-once:i": "node --experimental-vm-modules node_modules/jest/bin/jest.js -t \"\\`Temperature\\` class\"",
+    "test-once:j": "node --experimental-vm-modules node_modules/jest/bin/jest.js -t \"first \\`PlanarVector\\` class\"",
+    "test-once:k": "node --experimental-vm-modules node_modules/jest/bin/jest.js -t \"second \\`PlanarVector\\` class\"",
+    "test-once:l": "node --experimental-vm-modules node_modules/jest/bin/jest.js -t \"\\`Swappable\\` class\"",
+    "test-once:m": "node --experimental-vm-modules node_modules/jest/bin/jest.js -t \"\\`countDistinctElements\\` function\"",
+    "test-once:n": "node --experimental-vm-modules node_modules/jest/bin/jest.js -t \"\\`findMostCommonCharacter\\` function\"",
+    "test-once:o": "node --experimental-vm-modules node_modules/jest/bin/jest.js -t \"\\`summarize\\` function\"",
+    "test-once:p": "node --experimental-vm-modules node_modules/jest/bin/jest.js -t \"\\`formatArithmeticProgression\\` function\"",
+    "test-once:q": "node --experimental-vm-modules node_modules/jest/bin/jest.js -t \"\\`countArguments\\` function\"",
+    "test-once:r": "node --experimental-vm-modules node_modules/jest/bin/jest.js -t \"\\`Accumulator\\` class\"",
+    "test-once:s": "node --experimental-vm-modules node_modules/jest/bin/jest.js -t \"\\`makeBetweenFilter\\` function\"",
+    "test-once": "node --experimental-vm-modules node_modules/jest/bin/jest.js",
+    "test": "node --experimental-vm-modules node_modules/jest/bin/jest.js --watchAll"
+  },
+  "dependencies": {
+    "npm-run-all": "^4.1.5"
+  },
+  "devDependencies": {
+    "@unlsoft/eslint-config": "file:../eslint-config",
+    "eslint": "^8.20.0",
+    "jest": "^29.6.2",
+    "jest-environment-node": "^29.6.2"
+  },
+  "eslintConfig": {
+    "extends": "@unlsoft"
+  },
+  "jest": {
+    "clearMocks": true,
+    "collectCoverageFrom": [
+      "src/**/*.js",
+      "!src/testing/**/*.js"
+    ],
+    "resetMocks": false,
+    "restoreMocks": false,
+    "testEnvironment": "jest-environment-node",
+    "transform": {}
+  },
+  "//": [
+    "See https://github.com/facebook/jest/issues/9430 for information on Jest+ES6."
+  ]
+}

javascript-practice/src/aTemplateLiterals/templateLiterals.js

+export function formatAsTriple(x, y, z) {
+  // INSTRUCTIONS: Given three coordinates, return a template literal that
+  // formats them as a three-coordinate triple.  For example, formatAsTriple(4,
+  // 5, 6) should return the string '(4, 5, 6)'.
+  //
+  // Resources:
+  // <https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Template_literals>
+  // <https://javascript.info/types#string>
+  // <https://javascript.info/string#quotes>
+}

javascript-practice/src/aTemplateLiterals/templateLiterals.key.js

+export function formatAsTriple(x, y, z) {
+  return `(${x}, ${y}, ${z})`;
+}

javascript-practice/src/aTemplateLiterals/templateLiterals.test.js

+import { formatAsTriple } from './templateLiterals.js';
+
+describe('the `formatAsTriple` function', () => {
+  test('correctly formats the triple (0, 0, 0)', () => {
+    expect(formatAsTriple(0, 0, 0)).toBe('(0, 0, 0)');
+  });
+  test('correctly formats the triple (1, 2, 3)', () => {
+    expect(formatAsTriple(1, 2, 3)).toBe('(1, 2, 3)');
+  });
+  test('correctly formats the triple (-1, 2, -3)', () => {
+    expect(formatAsTriple(-1, 2, -3)).toBe('(-1, 2, -3)');
+  });
+});

javascript-practice/src/bConditionals/conditionals.js

+export function classify(number) {
+  let description = 'not a';
+  // INSTRUCTIONS: Use a chained conditional to set the variable `description`
+  // to 'negative' when number is negative, 'zero' when number is zero, and
+  // 'positive' when number is positive.  If number is none of those (for
+  // example, if number is NaN), leave the description as it is.
+  //
+  // Resources:
+  // <https://javascript.info/ifelse#several-conditions-else-if>
+  // <https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/if...else>
+  return `${description} number`;
+}

javascript-practice/src/bConditionals/conditionals.key.js

+export function classify(number) {
+  let description = 'not a';
+  if (number < 0) {
+    description = 'negative';
+  } else if (number === 0) {
+    description = 'zero';
+  } else if (number > 0) {
+    description = 'positive';
+  }
+  return `${description} number`;
+}

javascript-practice/src/bConditionals/conditionals.test.js

+import { classify } from './conditionals.js';
+
+describe('the `classify` function', () => {
+  test('correctly classifies a negative infinite number', () => {
+    expect(classify(-Infinity)).toBe('negative number');
+  });
+  test('correctly classifies a negative finite number', () => {
+    expect(classify(-4)).toBe('negative number');
+  });
+  test('correctly classifies zero', () => {
+    expect(classify(0)).toBe('zero number');
+  });
+  test('correctly classifies a positive finite number', () => {
+    expect(classify(4)).toBe('positive number');
+  });
+  test('correctly classifies a positive infinite number', () => {
+    expect(classify(Infinity)).toBe('positive number');
+  });
+  test('correctly classifies a NaN', () => {
+    expect(classify(NaN)).toBe('not a number');
+  });
+});

javascript-practice/src/cSwitchStatements/switchStatements.js

+/* eslint-disable no-magic-numbers */
+
+export function decodeCountingNumber(word) {
+  let meaning = undefined;
+  // INSTRUCTIONS: Use a switch statement to set meaning to 0, 1, 2, 3, or 4 if
+  // word is 'zero', 'one', two', 'three', or 'four', respectively.  Leave
+  // meaning undefined in the default case.
+  //
+  // Resources:
+  // <https://javascript.info/switch>
+  // <https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/switch>
+  return `The word "${word}" is associated with the meaning ${meaning}.`;
+}

javascript-practice/src/cSwitchStatements/switchStatements.key.js

+/* eslint-disable no-magic-numbers */
+
+export function decodeCountingNumber(word) {
+  let meaning = undefined;
+  switch (word) {
+  case 'zero':
+    meaning = 0;
+    break;
+  case 'one':
+    meaning = 1;
+    break;
+  case 'two':
+    meaning = 2;
+    break;
+  case 'three':
+    meaning = 3;
+    break;
+  case 'four':
+    meaning = 4;
+    break;
+  default:
+  }
+  return `The word "${word}" is associated with the meaning ${meaning}.`;
+}

javascript-practice/src/cSwitchStatements/switchStatements.test.js

+import { decodeCountingNumber } from './switchStatements.js';
+
+describe('the `decodeCountingNumber` function', () => {
+  test('correctly interprets the word "zero"', () => {
+    expect(decodeCountingNumber('zero')).toBe('The word "zero" is associated with the meaning 0.');
+  });
+  test('correctly interprets the word "one"', () => {
+    expect(decodeCountingNumber('one')).toBe('The word "one" is associated with the meaning 1.');
+  });
+  test('correctly interprets the word "two"', () => {
+    expect(decodeCountingNumber('two')).toBe('The word "two" is associated with the meaning 2.');
+  });
+  test('correctly interprets the word "three"', () => {
+    expect(decodeCountingNumber('three')).toBe('The word "three" is associated with the meaning 3.');
+  });
+  test('correctly interprets the word "four"', () => {
+    expect(decodeCountingNumber('four')).toBe('The word "four" is associated with the meaning 4.');
+  });
+  test('correctly interprets the word "five"', () => {
+    expect(decodeCountingNumber('five')).toBe('The word "five" is associated with the meaning undefined.');
+  });
+});

javascript-practice/src/dWhileLoops/whileLoops.js

+export function countDigits(positiveInteger) {
+  let result = 0;
+  let remainingDigits = positiveInteger;
+  // INSTRUCTIONS: Write a loop here that runs as long as `remainingDigits` is
+  // still positive, and on each iteration increments result and updates
+  // `remainingDigits` to `Math.floor(remainingDigits / 10)`.
+  //
+  // Resources:
+  // <https://javascript.info/while-for#the-while-loop>
+  // <https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/while>
+  // <https://javascript.info/operators#increment-decrement>
+  // <https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Increment>
+  // <https://javascript.info/number#rounding>
+  // <https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Math/floor>
+  return result;
+}

javascript-practice/src/dWhileLoops/whileLoops.key.js

+export function countDigits(positiveInteger) {
+  let result = 0;
+  let remainingDigits = positiveInteger;
+  while (remainingDigits > 0) {
+    ++result;
+    remainingDigits = Math.floor(remainingDigits / 10);
+  }
+  return result;
+}