Expt 1 - Part 1, Part 2 & Part 3

Explanation

Here is a clear breakdown of the Java program:

1. Purpose

This program sorts an array of integers in descending order (from largest to smallest) using a comparison-based sorting algorithm and prints the final sorted array.

2. Key Concepts

• Arrays: Storing and accessing multiple integer values in a single variable.
• Nested for Loops: Iterating through the array repeatedly to compare pairs of elements.
• Variable Swapping: Using a temporary variable (temp) to exchange two values in memory.
• Enhanced for Loop (For-Each): Traversing and displaying array elements cleanly.

3. Code Walkthrough

1. Array Initialization:
   int[] arr = {5, 2, 8, 1, 9}; creates an unsorted array of 5 integers.

2. Sorting Logic (Nested Loops):

   • Outer loop (i): Picks an index from the beginning to the end.
   • Inner loop (j): Compares the element at i with every element that comes after it (j = i + 1).

3. Comparison & Swap:

   • if (arr[i] < arr[j]) checks if a later element is larger than the current element.
   • If true, a standard 3-step swap moves the larger number to the left using temp.

4. Displaying Results:
   The for (int num : arr) loop prints each element sequentially after sorting is complete.

4. Output

Array elements in descending order: 9 8 5 2 1