Finished practice part of js basic arrays

01/app.js

@@ -0,0 +1,7 @@
+const users = ["Jan Kowalski", "Marta Kieliszek", "Zenon Gminny", "Albert Sosna", "Michał Bułka"]
+
+console.log(users[0]);
+console.log(users[2]);
+console.log(users[4]);
+
+console.log("Tablica zwiera =", users.length);

02/app.js

@@ -1,23 +1,33 @@
-const randomArray = createRandomArray();
-console.log(randomArray);
+const randomArray = createRandomArray()
+console.log(randomArray)
 
+for (let i = 0; i < randomArray.length; i++) {
+	console.log(randomArray[i])
+}
+
+randomArray.forEach(function (el) {
+	console.log(el)
+})
 
 
+console.log(randomArray[randomArray.length - 1]);
+
 // nie modyfikuj kodu poniżej!
 
 // funkcję może deklarować poniżej wywołania
 // ponieważ w JS występuje mechanizm tzw. hoisting-u
 
 function createRandomArray() {
-    const arr = [];
-    const len = getRandomInteger(1, 10)
-    for(let i=0; i<len; i++) {
-        arr.push( getRandomInteger(1, 100) );
-    }
+	const arr = []
+	const len = getRandomInteger(1, 10)
+	for (let i = 0; i < len; i++) {
+		arr.push(getRandomInteger(1, 100))
+	}
 
-    return arr;
+	console.log(arr)
+	return arr
 }
 
 function getRandomInteger(min, max) {
-    return Math.round(Math.random() * (max-min) + min);
-}
+	return Math.round(Math.random() * (max - min) + min)
+}

03/app.js

@@ -1,2 +1,21 @@
 const n = 24;
-const oddNumbers = [];
+const oddNumbers = [];
+
+
+
+for (let i=1; i<=n; i++) {
+
+    if (i % 2 !==0) {
+
+        oddNumbers.push(i)
+    }
+}
+
+console.log(oddNumbers);
+
+
+
+
+
+
+

04/app.js

@@ -1 +1,17 @@
-const years = [1980, 1934, 2002, 2019];
+const years = [1980, 1934, 2002, 2019];
+const differenceYearsArr = [];
+
+const currentDate = new Date();
+const currentYear = currentDate.getFullYear();
+
+// console.log(currentYear);
+
+years.forEach(function (el) {
+	// console.log(el);
+	const amountOfYears = currentYear - el;
+	// console.log(amountOfYears);
+
+	differenceYearsArr.push(amountOfYears);
+});
+
+console.log(differenceYearsArr);

05/app.js

@@ -1 +1,13 @@
-const numbers = [1, 2, 3, 4, 5, 6, 7];
+const numbers = [1, 2, 3, 4, 5, 6, 7];
+
+const evenNumbers = numbers.filter(function(el) {
+    return el % 2 === 0
+})
+
+console.log("Tablica z liczbami parzystymi", evenNumbers);
+
+const sumEvenNumbers = evenNumbers.reduce(function(a, b) {
+    return a + b;
+}, 0);
+
+console.log("Suma liczb parzystych to", sumEvenNumbers);