chapter 02 - arrays

Author: loiane

examples/chapter02/01-Introduction.js

@@ -1,12 +1,26 @@
-var averageTempJan = 31.9;
-var averageTempFeb = 35.3;
-var averageTempMar = 42.4;
-var averageTempApr = 52;
-var averageTempMay = 60.8;
+// @ts-check
 
-var averageTemp = [];
+const averageTempJan = 31.9;
+const averageTempFeb = 35.3;
+const averageTempMar = 42.4;
+const averageTempApr = 52;
+const averageTempMay = 60.8;
+
+const averageTemp = [];
 averageTemp[0] = 31.9;
 averageTemp[1] = 35.3;
 averageTemp[2] = 42.4;
 averageTemp[3] = 52;
 averageTemp[4] = 60.8;
+
+console.log(averageTempJan);
+console.log(averageTempFeb);
+console.log(averageTempMar);
+console.log(averageTempApr);
+console.log(averageTempMay);
+
+console.log(averageTemp[0]);
+console.log(averageTemp[1]);
+console.log(averageTemp[2]);
+console.log(averageTemp[3]);
+console.log(averageTemp[4]);

examples/chapter02/02-CreatingAndInitialingArrays.js

@@ -1,35 +1,37 @@
 // @ts-check
+/* eslint-disable */
 
-var daysOfWeek = [];
+let daysOfWeek = new Array(); // {1}
 
-var daysOfWeek = ['Sunday', 'Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday', 'Saturday'];
+daysOfWeek = new Array(7); // {2}
 
-var daysOfWeek = new Array(); // {1}
+daysOfWeek = new Array('Sunday', 'Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday', 'Saturday'); // {3}
 
-var daysOfWeek = new Array(7); // {2}
+// preferred
+daysOfWeek = [];
 
-console.log(daysOfWeek.length);
+daysOfWeek = ['Sunday', 'Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday', 'Saturday']; // {3}
 
-var daysOfWeek = new Array('Sunday', 'Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday', 'Saturday'); // {3}
+console.log(daysOfWeek.length);
 
-for (var i = 0; i < daysOfWeek.length; i++) {
+for (let i = 0; i < daysOfWeek.length; i++) {
   console.log(daysOfWeek[i]);
 }
 
 // console.table(daysOfWeek);
 
 // fibonacci numbers
 // 0, 1, 1, 2, 3, 5, 8, 13, 21, 34, ...
-var fibonacci = []; // {1}
-fibonacci[1] = 1;   // {2}
-fibonacci[2] = 1;   // {3}
+const fibonacci = []; // {1}
+fibonacci[1] = 1; // {2}
+fibonacci[2] = 1; // {3}
 
-for (var i = 3; i < 20; i++) {
+for (let i = 3; i < 20; i++) {
   fibonacci[i] = fibonacci[i - 1] + fibonacci[i - 2]; // //{4}
 }
 
-for (var i = 1; i < fibonacci.length; i++) { // {5}
-  console.log(fibonacci[i]);                 // {6}
+for (let i = 1; i < fibonacci.length; i++) { // {5}
+  console.log(fibonacci[i]); // {6}
 }
 
 // instead of {5} and {6} we can simply use

examples/chapter02/03-AddingRemovingElements.js

@@ -1,13 +1,14 @@
 // @ts-check
 
+const numbers = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9];
+
+
 function printArray(myArray) {
-  for (var i = 0; i < myArray.length; i++) {
+  for (let i = 0; i < myArray.length; i++) {
     console.log(myArray[i]);
   }
 }
 
-var numbers = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9];
-
 // add a new element to the numbers array
 numbers[numbers.length] = 10;
 
@@ -18,7 +19,7 @@ numbers.push(12, 13);
 printArray(numbers);
 
 // insert first position manually
-for (var i = numbers.length; i >= 0; i--) {
+for (let i = numbers.length; i >= 0; i--) {
   numbers[i] = numbers[i - 1];
 }
 
@@ -40,9 +41,9 @@ printArray(numbers);
 numbers.pop();
 
 // remove first position manually
-/* for (var i=0; i<numbers.length; i++){
-    numbers[i] = numbers[i+1];
-}*/
+for (let i = 0; i < numbers.length; i++) {
+  numbers[i] = numbers[i + 1];
+}
 
 printArray(numbers);
 

examples/chapter02/04-TwoDimensionalMultiDimensional.js

@@ -1,17 +1,18 @@
 // @ts-check
+/* eslint-disable */
 
-var averageTempDay1 = [72, 75, 79, 79, 81, 81];
-var averageTempDay2 = [81, 79, 75, 75, 73, 72];
+let averageTempDay1 = [72, 75, 79, 79, 81, 81];
+let averageTempDay2 = [81, 79, 75, 75, 73, 72];
 
-var averageTemp = [];
+let averageTemp = [];
 
 // same as
 averageTemp[0] = [72, 75, 79, 79, 81, 81];
 averageTemp[1] = [81, 79, 75, 75, 73, 72];
 
 function printMatrix(myMatrix) {
-  for (var i = 0; i < myMatrix.length; i++) {
-    for (var j = 0; j < myMatrix[i].length; j++) {
+  for (let i = 0; i < myMatrix.length; i++) {
+    for (let j = 0; j < myMatrix[i].length; j++) {
       console.log(myMatrix[i][j]);
     }
   }
@@ -44,20 +45,20 @@ printMatrix(averageTemp);
 
 // Matrix 3x3x3 - Cube
 
-var matrix3x3x3 = [];
-for (var i = 0; i < 3; i++) {
+const matrix3x3x3 = [];
+for (let i = 0; i < 3; i++) {
   matrix3x3x3[i] = [];
-  for (var j = 0; j < 3; j++) {
+  for (let j = 0; j < 3; j++) {
     matrix3x3x3[i][j] = [];
-    for (var z = 0; z < 3; z++) {
+    for (let z = 0; z < 3; z++) {
       matrix3x3x3[i][j][z] = i + j + z;
     }
   }
 }
 
-for (var i = 0; i < matrix3x3x3.length; i++) {
-  for (var j = 0; j < matrix3x3x3[i].length; j++) {
-    for (var z = 0; z < matrix3x3x3[i][j].length; z++) {
+for (let i = 0; i < matrix3x3x3.length; i++) {
+  for (let j = 0; j < matrix3x3x3[i].length; j++) {
+    for (let z = 0; z < matrix3x3x3[i][j].length; z++) {
       console.log(matrix3x3x3[i][j][z]);
     }
   }