Java Examples
Dave Braunschweig
Arrays
// This program demonstrates array processing, including: // display, total, max, min, parallel arrays, sort, // fixed arrays, dynamic arrays, and multidimensional arrays. import java.util.*; class Main { public static void main(String[] args) { String[] names = {"Lisa", "Michael", "Ashley", "Jacob", "Emily"}; int[] ages = {49, 48, 26, 19, 16}; displayArray(ages); int total = calculateSum(ages); int maximum = calculateMaximum(ages); int minimum = calculateMinimum(ages); System.out.println("total: " + total); System.out.println("maximum: " + maximum); System.out.println("minimum: " + minimum); demonstrateParallelArrays(names, ages); Arrays.sort(ages); displayArray(ages); demonstrateFixedArray(); demonstrateDynamicArray(); demonstrateMultidimensionalArray(); } public static void displayArray(int[] array) { for (int index = 0; index < array.length; index++) { System.out.println("array[" + index + "] = " + array[index]); } } public static int calculateSum(int[] array) { int total = 0; for (int index = 0; index < array.length; index++) { total += array[index]; } return total; } public static int calculateMaximum(int[] array) { int maximum = array[0]; for (int index = 1; index < array.length; index++) { if (maximum < array[index]) { maximum = array[index]; } } return maximum; } public static int calculateMinimum(int[] array) { int minimum = array[0]; for (int index = 1; index array[index]) { minimum = array[index]; } } return minimum; } public static void demonstrateParallelArrays(String[] names, int[] ages) { for (int index = 0; index < names.length; index++) { System.out.println(names[index] + " is " + ages[index] + " years old"); } } public static void demonstrateFixedArray() { int[] array = new int[5]; for (int index = 0; index < array.length; index++) { int number = (int) Math.floor(Math.random() * 100); array[index] = number; } displayArray(array); } public static void demonstrateDynamicArray() { ArrayList array = new ArrayList(); for (int index = 0; index < 5; index++) { int number = (int) Math.floor(Math.random() * 100); array.add(number); } System.out.println(array); } public static void demonstrateMultidimensionalArray() { String[][] game = { {"X", "O", "X"}, {"O", "O", "O"}, {"X", "O", "X"} }; for (int row = 0; row < 3; row++) { for (int column = 0; column < 3; column++) { System.out.print(game[row][column]); if (column < 2) { System.out.print(" | "); } } System.out.println(); } } }
Output
array[0] = 49 array[1] = 48 array[2] = 26 array[3] = 19 array[4] = 16 total: 158 maximum: 49 minimum: 16 Lisa is 49 years old Michael is 48 years old Ashley is 26 years old Jacob is 19 years old Emily is 16 years old array[0] = 16 array[1] = 19 array[2] = 26 array[3] = 48 array[4] = 49 array[0] = 28 array[1] = 30 array[2] = 28 array[3] = 75 array[4] = 21 [56, 50, 63, 82, 15] X | O | X O | O | O X | O | X