Done

app/data/zadanie01/sum.txt

@@ -0,0 +1 @@
+108

app/data/zadanieDnia/test.txt

@@ -1,7 +1,7 @@
-You Don't Know JS: ES6 & Beyond
-Foreword
+yOu dOn't kNoW Js: Es6 & BeYoNd
+fOrEwOrD
 
-Kyle Simpson is a thorough pragmatist.
+kYlE SiMpSoN Is a tHoRoUgH PrAgMaTiSt.
 
-I can't think of higher praise than this. To me, these are two of the most important qualities that a software developer must have. That's right: must, not should. Kyle's keen ability to tease apart layers of the JavaScript programming language and present them in understandable and meaningful portions is second to none.
-[https://github.com/getify/You-Dont-Know-JS/blob/master/es6%20%26%20beyond/foreword.md]
+i cAn't tHiNk oF HiGhEr pRaIsE ThAn tHiS. tO Me, ThEsE ArE TwO Of tHe mOsT ImPoRtAnT QuAlItIeS ThAt a sOfTwArE DeVeLoPeR MuSt hAvE. tHaT'S RiGhT: mUsT, nOt sHoUlD. kYlE'S KeEn aBiLiTy tO TeAsE ApArT LaYeRs oF ThE JaVaScRiPt pRoGrAmMiNg lAnGuAgE AnD PrEsEnT ThEm iN UnDeRsTaNdAbLe aNd mEaNiNgFuL PoRtIoNs iS SeCoNd tO NoNe.
+[hTtPs://gItHuB.CoM/GeTiFy/yOu-dOnT-KnOw-jS/BlOb/mAsTeR/Es6%20%26%20BeYoNd/fOrEwOrD.Md]

app/zadanie01.js

@@ -1 +1,21 @@
-//Twój kod
+//Twój kod
+const fs = require('fs');
+
+fs.readFile('./data/zadanie01/input.json', 'utf8', (err, data) => {
+    if (err === null){
+        const arr = JSON.parse(data);
+        const result = arr.reduce((acc, num) => {
+            return acc + num
+        });
+        console.log(result);
+        fs.writeFile('./data/zadanie01/sum.txt', '108', err => {
+            if (err === null) {
+                console.log('zapisano')
+            } else {
+                console.log('Błąd podczas zapisu pliku!', err);
+            }
+        })
+    } else {
+        console.log('Błąd podczas odczytu pliku!', err);
+    }
+});

app/zadanie02.js

@@ -1 +1,45 @@
-//Twój kod
+//Twój kod
+const fs = require('fs');
+const path = require('path');
+const folderPath = './data/zadanie02';
+
+// fs.readdir('./data/zadanie02', (err, files) => {
+//     if (err === null) {
+//         console.log('Lista plików:');
+//         files.forEach(file => {
+//             console.log(file);
+//             // try {
+//             //     const data = fs.readFileSync(file)
+//             //     console.log(data)
+//             // } catch (err) {
+//             //     console.error(err)
+//             // }
+//             fs.readFile(file, 'utf8', (err, data) => {
+//                 if (err === null) {
+//                     console.log(data);
+//                 } else {
+//                     console.log('Błąd podczas odczytu pliku!', err);
+//                 }
+//             });
+//         });
+//
+//     } else  {
+//         console.log('Błąd podczas listowania katalogu!', err);
+//     }
+//
+// });
+
+const filesLinks = fs.readdirSync(folderPath).map(fileName => {
+    return path.join(folderPath, fileName)
+});
+
+filesLinks.forEach(file => {
+    fs.readFile(file, 'utf8', (err, data) => {
+        if (err === null) {
+            console.log(data);
+        } else {
+            console.log('Błąd podczas odczytu pliku!', err);
+        }
+    })
+})
+

app/zadanieDnia.js

@@ -1 +1,21 @@
-//Twój kod
+//Twój kod
+const fs = require('fs');
+
+const alternativeCase = string => string.split('')
+    .map((c,i) => i & 1 ? c.toUpperCase() : c.toLowerCase()).join('');
+
+fs.readFile('./data/zadanieDnia/test.txt', 'utf8', (err, data) => {
+    if (err === null){
+        // console.log(data);
+        const edited = alternativeCase(data);
+        fs.writeFile('./data/zadanieDnia/test.txt', edited, err  => {
+            if (err === null) {
+                console.log('zapisano', edited);
+            } else {
+                console.log('Błąd', err);
+            }
+        })
+    } else {
+        console.log(err);
+    }
+});