Change week 3 step2-6 to flatten an array

remarcmij · remarcmij · commit 92d734b4c3f2 · 2019-01-26T18:44:56.000+01:00
diff --git a/Week3/MAKEME.md b/Week3/MAKEME.md
@@ -112,8 +112,13 @@ const arr2d = [[1, 2], [3, 4], [5, 6]];
 
 (for math people you can think of this as a matrix)
 
-How would you print all the items of an array with 3 dimensions?
-How about with _K_ dimensions?
+How would you flatten out all the items of an array with 2 dimensions into a one-dimensional array? Flattening out the `arr2d` array above would result in:
+
+```js
+const flattenedArr = [1, 2, 3, 4, 5, 6];
+```
+
+How about 3 dimensions? How about with _K_ dimensions?
 What if you didn't know how deep the array was nested? (You don't have to write code for this but think about it.)
 
 **2.7** Here are two functions that look like they do the something similar but they print different results. Please explain what's going on here.
diff --git a/Week3/homework/step2-6.js b/Week3/homework/step2-6.js
@@ -3,21 +3,21 @@
 const arr2d = [[1, 2], [3, 4], [5, 6]];
 const arr3d = [[[1, 2], [3, 4]], [[5, 6], [7, 8]]];
 
-function printArray2d(arr) {
+function flattenArray2d(arr) {
   // Replace this comment and the next line with your code
   console.log(arr);
 }
 
-function printArray3d(arr) {
+function flattenArray3d(arr) {
   // Replace this comment and the next line with your code
   console.log(arr);
 }
 
-printArray2d(arr2d);
-printArray3d(arr3d);
+console.log(flattenArray2d(arr2d)); // -> [1, 2, 3, 4, 5, 6]
+console.log(flattenArray3d(arr3d)); // -> [1, 2, 3, 4, 5, 6, 7, 8]
 
 // Do not change or remove anything below this line
 module.exports = {
-  printArray2d,
-  printArray3d
+  flattenArray2d,
+  flattenArray3d
 };
diff --git a/Week3/test/step2-6.test.js b/Week3/test/step2-6.test.js
@@ -1,27 +1,20 @@
 /* eslint-disable no-return-assign, dot-notation */
-const { printArray2d, printArray3d } = require('../homework/step2-6');
+const { flattenArray2d, flattenArray3d } = require('../homework/step2-6');
 
 const arr2d = [[1, 2], [3, 4], [5, 6]];
-const expected2d = [1, 2, 3, 4, 5, 6].join('');
+const expected2d = [1, 2, 3, 4, 5, 6];
 
 const arr3d = [[[1, 2], [3, 4]], [[5, 6], [7, 8]]];
-const expected3d = [1, 2, 3, 4, 5, 6, 7, 8].join('');
+const expected3d = [1, 2, 3, 4, 5, 6, 7, 8];
 
 describe('step2-6', () => {
-  let outputData;
-  const storeLog = (...inputs) => (outputData += inputs.join(' '));
-
-  test('printArray2d -> 1, 2, 3, 4, 5, 6', () => {
-    outputData = '';
-    console['log'] = jest.fn(storeLog);
-    printArray2d(arr2d);
-    expect(outputData).toBe(expected2d);
+  test('flattenArray2d -> [1, 2, 3, 4, 5, 6]', () => {
+    const result = flattenArray2d(arr2d);
+    expect(result).toEqual(expected2d);
   });
 
-  test('printArray3d -> 1, 2, 3, 4, 5, 6, 7, 8', () => {
-    outputData = '';
-    console['log'] = jest.fn(storeLog);
-    printArray3d(arr3d);
-    expect(outputData).toBe(expected3d);
+  test('flattenArray3d -> [1, 2, 3, 4, 5, 6, 7, 8]', () => {
+    const result = flattenArray3d(arr3d);
+    expect(result).toEqual(expected3d);
   });
 });
