Course New Java Syntax - Lecture: Basic actions with arrays

"Here are a few examples of interesting things you can do with arrays:"

Example 1.

Fill a 10-element array with numbers from 1 to 10:

public class MainClass
 {
     public static void main(String[] args)
     {
         int[] numbers = new int[10];

         for (int i = 0; i < numbers.length; i++)
         {
            numbers[i] = i + 1;
         }
     }
 }

Fill a 10-element array with numbers from 10 to 1:

public class MainClass
 {
     public static void main(String[] args)
     {
         int[] numbers = new int[10];

         for (int i = 0; i < numbers.length; i++)
         {
            numbers[i] = 10 - i;
         }
     }
 }

Fill a 10-element array with numbers from 0 to 9:

public class MainClass
 {
     public static void main(String[] args)
     {
         int[] numbers = new int[10];

         for (int i = 0; i < numbers.length; i++)
         {
            numbers[i] = i;
         }
     }
 }

Fill a 10-element array with numbers from 9 to 0:

public class MainClass
 {
     public static void main(String[] args)
     {
         int[] numbers = new int[10];

         for (int i = 0; i < numbers.length; i++)
         {
            numbers[i] = 9 - i;
         }
     }
 }

Example 2.

Read 10 strings from the keyboard:

public class MainClass
 {
   public static void main(String[] args) throws IOException
   {
     BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
     String[] list = new String[10];

     for (int i = 0; i < list.length; i++)
     {
       list[i] = reader.readLine();
      }
   }
 }

Read 10 numbers from the keyboard:

public class MainClass
 {
   public static void main(String[] args) throws IOException
   {
     BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
     int[] list = new int[10];

     for (int i = 0; i < list.length; i++)
     {
       String s = reader.readLine();
       list[i] = Integer.parseInt(s);
     }
   }
 }

Example 3.

Display an array on the screen:

public class MainClass
 {
     public static void main(String[] args) throws IOException
     {
         int[] list = new int[10];

         // Fill the array
         for (int i = 0; i < list.length; i++)
         {
            list[i] = i;
         }

         // Display the contents of the array
         for (int i = 0; i < list.length; i++)
        {
           System.out.println(list[i]);
        }
     }
 }

Example 4.

Quick (static) initialization. Add up the array elements:

public class MainClass
 {
     public static void main(String[] args) throws IOException
     {
         // Static initialization
         int[] list = {5, 6, 7, 8, 1, 2, 5, -7, -9, 2, 0};

         // Calculate the sum
         int sum = 0;
         for (int i = 0; i < list.length; i++)
         {
            sum += list[i];
         }

         System.out.println("Sum is " + sum);
     }
 }

Example 5.

Find the smallest element in an array:

public class MainClass
 {
     public static void main(String[] args) throws IOException
     {
         int[] list = {5, 6, 7, 8, 1, 2, 5, -7, -9, 2, 0};

         int min = list[0];
         for (int i = 1; i < list.length; i++)
         {
              if (list[i] < min)
              {
                   min = list[i];
              }
         }

        System.out.println ("Min is " + min);
     }
 }