Expt 1 - Part 1, Part 2 & Part 3

Explanation

This Java program is designed to demonstrate how to create, populate, and display a one-dimensional (1D) array using user input. It first prompts the user to specify the desired number of elements for the array. Based on this input, it creates an integer array of that exact size. Then, it iteratively asks the user to enter each individual element, storing them sequentially in the array. Finally, after all elements have been entered, the program prints the entire user-defined array to the console in a readable format.

The core logic involves:

1. Getting Array Size: Asking the user how many elements they want in the array.
2. Array Creation: Allocating memory for an integer array of the specified size.
3. Populating the Array: Using a loop to repeatedly prompt the user for an integer and store it in the next available position in the array.
4. Displaying the Array: Using another loop to iterate through the array and print each stored element to the console.
5. Resource Management: Closing the input scanner to prevent resource leaks.

Algorithm

The algorithm used in this program can be broken down into the following steps:

1. Initialize Scanner: Create a Scanner object to read input from the console.
2. Prompt for Size: Display a message asking the user to enter the desired size of the array.
3. Read Size: Read the integer value entered by the user and store it in a variable named size.
4. Declare and Instantiate Array: Declare an integer array variable and create a new array object of the size specified by the user.
5. Populate Array Loop:
   • Start a for loop that iterates from i = 0 up to (but not including) size.
   • Inside the loop, prompt the user to "Enter element X" (where X is i+1 for user-friendly counting).
   • Read the integer value entered by the user.
   • Store this integer value at the current index i of the array.
6. Print Array Header: Display the introductory text "User Defined 1D Array: [" to the console.
7. Display Array Elements Loop:
   • Start a for loop that iterates from i = 0 up to (but not including) the length of the array.
   • Inside the loop, print the element at the current index i of the array, followed by a comma and a space (, ).
8. Print Array Footer: Display a closing square bracket ] and a newline character to complete the array's representation.
9. Close Scanner: Close the Scanner object to release system resources.