Expt 1 - Part 1, Part 2 & Part 3

Explanation

This Java program, named array_1d, demonstrates how to declare, initialize, and print the elements of a one-dimensional (1D) array. In this specific context, the array is considered "static" because its size and initial values are fixed and defined directly within the code at compile time, rather than being determined during runtime (e.g., from user input).

Here's a step-by-step breakdown of the logic:

1. Class Definition: The program starts by defining a public class named array_1d. In Java, all code resides within classes.
2. Main Method: Inside the array_1d class, there's a public static void main(String[] args) method. This is the entry point of any Java application. When you run this program, the Java Virtual Machine (JVM) looks for and executes the code within this main method.
3. Array Declaration and Initialization:

   int[] num = {2,5,7,12,10};
   

   This line declares an array named num that can hold integer (int) values. It then immediately initializes this array with five specific integer values: 2, 5, 7, 12, and 10. The size of the array is automatically determined by the number of elements provided in the initializer list.
4. Printing Introductory Text:

   System.out.print("Static 1D Array: [");
   

   This line prints the literal string "Static 1D Array: [" to the console. Notice System.out.print is used, which means the cursor will remain on the same line after printing, allowing subsequent output to appear immediately after.
5. Iterating Through the Array (Loop):

   for(int i=0; i<num.length; i++){
       System.out.print(num[i] + ", ");
   }
   

   A for loop is used to go through each element of the array.
   • int i=0: Initializes a loop counter variable i to 0. Array indices in Java (and many other languages) start from 0.
   • i<num.length: This is the loop condition. num.length is a property that returns the total number of elements in the num array (which is 5 in this case). The loop continues as long as i is less than 5.
   • i++: After each iteration of the loop, the value of i is incremented by 1.
   • System.out.print(num[i] + ", ");: Inside the loop, num[i] accesses the element at the current index i. This element's value is then printed, followed by a comma and a space. This happens for each element (2, then 5, then 7, etc.).
6. Printing Closing Bracket:

   System.out.println("]");
   

   After the loop has finished iterating through all elements, this line prints the closing bracket "]" to the console. System.out.println is used here, which means after printing the bracket, the cursor will move to the next line, ensuring any subsequent output (if any) starts on a fresh line.

In essence, the program prints a descriptive label, then iterates through the fixed array, printing each number followed by a comma and space, and finally closes the output with a bracket.

Algorithm

The algorithm used in this Java program to print a static 1D array can be described as follows:

1. Start Program: Begin the execution of the Java application.
2. Declare and Initialize Array: Create a one-dimensional integer array and populate it with a predefined set of values.
3. Print Opening String: Output a descriptive label along with an opening square bracket to the console, without moving to a new line.
4. Iterate Through Array Elements:
   • Initialize a counter variable (e.g., i) to 0.
   • Loop Condition: Continue iterating as long as the counter variable is less than the total number of elements in the array.
   • Access and Print Element: In each iteration, retrieve the array element at the current index specified by the counter variable.
   • Format Output: Print the retrieved element, followed by a comma and a space, without moving to a new line.
   • Increment Counter: Increase the counter variable by 1 for the next iteration.
5. Print Closing String: Once all elements have been processed by the loop, output a closing square bracket to the console, and then move the cursor to the next line.
6. End Program: Terminate the execution of the Java application.