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 = sum(ages);
int maximum = max(ages);
int minimum = min(ages);
System.out.println("total: " + total);
System.out.println("maximum: " + maximum);
System.out.println("minimum: " + minimum);
displayParallel(names, ages);
Arrays.sort(ages);
displayArray(ages);
fixedArray();
dynamicArray();
displayMultidimensional();
}
public static void displayArray(int[] array) {
for (int index = 0; index < array.length; index++) {
System.out.println("array[" + index + "] = " + array[index]);
}
}
public static int sum(int[] array) {
int total = 0;
for (int index = 0; index < array.length; index++) {
total += array[index];
}
return total;
}
public static int max(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 min(int[] array) {
int minimum = array[0];
for (int index = 1; index array[index]) {
minimum = array[index];
}
}
return minimum;
}
public static void displayParallel(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 fixedArray() {
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 dynamicArray() {
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 displayMultidimensional() {
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
