Add: Arrays Examples

DouglasHdezT · DouglasHdezT · commit 941fd232288b · 2020-02-15T22:32:58.000-06:00
diff --git a/5-Arrays/Example1.js b/5-Arrays/Example1.js
@@ -0,0 +1,57 @@
+'use-strict'
+
+/**
+ * Push, pop, unshift, shift
+ */
+
+let array1 = [9, 5, 6, 3];
+let array2 = [1, 2, 3, 4, 5];
+
+/**
+ * Push and pop, adds and remove items at the end of the array respectively
+ */
+
+const manageArrayAtTheEnd = () => {
+    console.log("Manage Array at end ");
+    
+    console.log("Pushing one element");
+    
+    array1.push(3);
+    console.log(array1);
+    
+    console.log("Pushing several elements");
+
+    array1.push(2,4,3,5,2);
+    console.log(array1);
+
+    console.log("Poping one element");
+
+    console.log(array1.pop());
+    console.log(array1);
+}
+
+/**
+ * Shift and unshift adds and remove items at the begin of the array respectively
+ */
+
+const manageArrayAtTheBegin = () => {
+    console.log("manage Array at the begin");
+    
+    console.log("Unshift one element");
+    
+    array2.unshift(4)
+    console.log(array2);
+    
+    console.log("Unshifting several elements");
+
+    array2.unshift(6,4,3,5,2);
+    console.log(array2);
+
+    console.log("shift one element");
+
+    console.log(array2.shift());
+    console.log(array2);
+}
+
+manageArrayAtTheEnd();
+manageArrayAtTheBegin();
diff --git a/5-Arrays/Example2.js b/5-Arrays/Example2.js
@@ -0,0 +1,43 @@
+'use-strict'
+
+/**
+ * Concat, slice and splice
+ */
+
+let array1 = [1, 2, 3, 4];
+let array2 = [4, 3, 2, 1];
+
+/**
+ * Concat join two arrays, and return a new instace of Array with the result. Dont alter both originals arrays
+ */
+
+const concatArrays = () => {
+    let array3 = array1.concat(array2);
+    console.log(array3);
+}
+
+/**
+ * Slice return a copy of part of an array in a new instace of Array. Dont alter original array.
+ */
+
+const sliceArrays = () => {
+    //The begin position is included, and the end position is excluded
+    let arraySliced = array1.slice(0, 2);
+    console.log(arraySliced);
+}
+
+/**
+ * Splice returns a part of an array, deleting it from the original array.
+ */
+
+const spliceArrays = () => {
+    //The begin position is included, and the end position is excluded
+    let arraySpliced = array1.splice(0, 2);
+    console.log(`Subarray: ${arraySpliced}`);
+    console.log(`New array: ${array1}`);
+    
+}
+
+concatArrays();
+sliceArrays();
+spliceArrays();
diff --git a/5-Arrays/Example3.js b/5-Arrays/Example3.js
@@ -0,0 +1,30 @@
+'use-strict'
+
+/**
+ * For each; it's used to go through an array; you can know every item with its position in every iteration
+ */
+
+let array = [1, 9, 8, 2, 7, 3, 6 ,4, 5];
+
+const oddEven = () =>{
+
+    array.forEach(element => {
+
+        element % 2 == 0 ? console.log("Even"): console.log("Odd");
+
+    });
+
+}
+
+const listAllElements = () => {
+
+    array.forEach((element, index) => {
+        
+        console.log(`${index}: ${element}`);
+    
+    });
+
+}
+
+oddEven();
+listAllElements();
diff --git a/5-Arrays/Example4.js b/5-Arrays/Example4.js
@@ -0,0 +1,23 @@
+/**
+ * Filter; it's used to filter array items that fullfill a condition. Returns a new instance of Array.
+ */
+
+let books = [
+    "Cien años de soledad",
+    "Rayuela",
+    "El padrino",
+    "Simbolo perdido",
+    "El Tunel",
+    "El retrato de Dorian Grey"
+]
+
+const filterEBooks = () => {
+    let ebooks = books.filter(element =>{
+        return element.charAt(0) == "E";
+    });
+
+    console.log(ebooks);
+    
+}
+
+filterEBooks();
diff --git a/5-Arrays/Example5.js b/5-Arrays/Example5.js
@@ -0,0 +1,34 @@
+/**
+ * Map; Apply a function to every item in an array, returning a new array with the items modified; Returns a new instance of Array
+ */
+
+let numbers = [1, 2, 3, 4, 5];
+let persons = [
+    {name: "Douglas", lastname: "Hernandez"},
+    {name: "Pedro", lastname: "Gomez"},
+] 
+
+const arrayTimesX = x => {
+    let newArray = numbers.map(element => {
+        return element * x;
+    });
+
+    console.log(newArray);
+}
+
+const listFullnames = () => {
+    let fullnames = persons.map(element => {
+        let fullname = `${element.name} ${element.lastname}`;
+        return fullname;
+    });
+
+    console.log(fullnames);
+    
+}
+
+arrayTimesX(2);
+arrayTimesX(3);
+arrayTimesX(4);
+arrayTimesX(5);
+
+listFullnames();
diff --git a/5-Arrays/Example6.js b/5-Arrays/Example6.js
@@ -0,0 +1,45 @@
+/**
+ * Reduce; It reduce the complete array into a single result; it use every element in a formula and the result is joined with an acumulator.
+ * Returns the acumulator
+ */
+
+let books = [
+    "Cien años de soledad",
+    "Rayuela",
+    "El padrino",
+    "Simbolo perdido",
+    "El Tunel",
+    "El retrato de Dorian Grey"
+]
+
+let numbers = [1, 2, 3, 4, 5];
+
+let addAllNumbers = () => {
+    let acumulator = numbers.reduce ((curResult, element) => {
+        return curResult + element;
+    })
+
+    console.log(acumulator);
+}
+
+let subAllNumbers = () => {
+    let acumulator = numbers.reduce ((curResult, element) => {
+        return curResult - element;
+    });
+
+    console.log(acumulator);
+}
+
+let showBookshelf = () => {
+    let myBookshelf = books.reduce((result, book) =>{
+        return result + `${book}, `;
+    }, "My Bookshelf is: ");
+
+    myBookshelf = myBookshelf.slice(0, -1);
+    console.log(myBookshelf);
+    
+}
+
+addAllNumbers(); 
+subAllNumbers();
+showBookshelf();
