Introduction

• A one-dimensional array is the simplest form of an array in Java.
• It stores a collection of elements of the same data type in a linear sequence.
• Each element in the array can be accessed using a single index.
• It is often used to represent lists, such as marks of students, prices of products, or names in a list.
• For example :
  • int[] marks = {88, 74, 91, 82, 68, 94};
  • 

Working with 1D Arrays:

• To work with 1D arrays in Java, we need to learn the following steps:
  1. Declare an array - Define the reference of the array with a specific data type.
  2. Create an array - Allocate memory for the array using the new keyword.
  3. Initialize an array - Assign values to the elements of the array.
  4. Retrieve elements of an array - Access array elements using their index.
• We will go through each step with examples below.

Array Programs:-

• Program 1:

  public class MainApp1
  {
      public static void main(String[] args)
      {
  
          // 1. Declare and create an array of size 6
          int[] marks = new int[6];
  
          // 2. Initialize array elements
          marks[0] = 88;
          marks[1] = 74;
          marks[2] = 91;
          marks[3] = 82;
          marks[4] = 68;
          marks[5] = 94;
  
          // 3. Access and print array elements using normal for loop (Way 1)
          System.out.print("Way 1: ");
          for (int i = 0; i < marks.length; i++)
          {
              System.out.print(marks[i] + " ");
          }
          System.out.println(); // Move to next line
  
          // 4. Access and print array elements using for-each loop (Way 2)
          System.out.print("Way 2: ");
          for (int no : marks)
          {
              System.out.print(no + " ");
          }
          System.out.println(); // Move to next line
      }
  }

  Output:

  Way 1: 88 74 91 82 68 94 
  Way 2: 88 74 91 82 68 94 

  • Points to note:
    • We have accessed the array elements in 2 ways, i.e., using normal for loop and for-each loop. But for-each loop is preferred as it is simple and easy to understand.
    • Declaring and creating array like above is lengthy. We can also declare, create, and initialize the array in a single line using shorthand notation as shown in Program 2 below.
• Program 2:

  public class MainApp2
  {
      public static void main(String[] args)
      {
          // 1. Declare and create an array using shorthand notation
          // This automatically initializes the array with the given values
          int[] marks = {88, 74, 91, 82, 68, 94};
  
          // 2. Access and print array elements using a for-each loop
          // The variable 'no' takes the value of each element sequentially
          System.out.print("Marks are: ");
          for (int no : marks)
          {
              System.out.print(no + " "); // Print each element
          }
      }
  }

  Output:

  Marks are: 88 74 91 82 68 94

  • Points to note:
    • In this program, we have declared, created, and initialized the array in a single line using shorthand notation.
    • We have accessed the array elements using for-each loop, which is the more preferred way.