C# Collections Evolution: From Arrays to Generics

Overview

This comprehensive example demonstrates the evolution of data storage in C#, from basic arrays to modern generic collections. It shows various data structures, their problems, and solutions, along with performance considerations and best practices.

1. Employee Objects Setup

Code:

Emp emp1 = new Emp();
emp1.No = 1;
emp1.Name = "Jayesh";
emp1.Address = "Karad";
emp1.EMail = "[email protected]";

// Similar for emp2 and emp3...

Purpose:

Creates three sample Employee objects to demonstrate various collection operations throughout the examples.

2. Integer Array - Fixed Size Limitations

Code Analysis:

// Method 1: Declaration then assignment
int[] arr = new int[3];
arr[0] = 99;
arr[1] = 22;
arr[2] = 55;
// arr[3] = 30; // IndexOutOfRangeException!

// Method 2: Initialization
int[] arr = new int[] { 10, 20, 30, 40, 50 };

for (int i = 0; i < arr.Length; i++)
{
    Console.WriteLine(arr[i]);
}

Key Points:

• Fixed Size: Arrays have compile-time fixed size
• Index Bounds: Accessing arr[3] when size is 3 throws exception
• Type Safety: Can only store integers
• Performance: Fastest access (direct memory indexing)

Problems:

• Cannot resize after creation