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Ravi Vishwakarma

Ravi Vishwakarma

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Hi, my self Ravi Vishwakarma. I have completed my studies at SPICBB Varanasi. now I completed MCA with 76% form Veer Bahadur Singh Purvanchal University Jaunpur. SWE @ MindStick | Software Engineer | Web Developer | .Net Developer | Web Developer | Backend Engineer | .NET Core Developer

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Ravi Vishwakarma

Ravi Vishwakarma

09-Jun-2024

The foreach loop in C# is used to iterate over a collection of items, such as arrays, lists, or other enumerable collections. It is beneficial for iterating through elements without knowing the collection size or managing loop counters. The foreach loop provides a cleaner and more readable way to traverse collections than the traditional for loop.

Here is the basic syntax of a foreach loop in C#:

foreach (var item in collection)
{
    // Code to execute for each item
}

Example Usage

Iterating Over an Array:

int[] numbers = { 1, 2, 3, 4, 5 };

foreach (int number in numbers)
{
    Console.WriteLine(number);
}

Iterating Over a List:

List<string> names = new List<string> { "Alice", "Bob", "Charlie" };

foreach (string name in names)
{
    Console.WriteLine(name);
}

 

Key Points

  • The foreach loop can only be used with collections that implement the IEnumerable interface.
  • The loop variable (e.g., item in the examples) is read-only within the scope of the loop. You cannot assign a new value to item within the loop body.
  • The foreach loop automatically handles the iteration bounds, so you do not need to manage index variables manually.
  • It is generally safer and less error-prone than using a for loop with index variables, especially when working with collections that can change in size or when the iteration logic is complex.

Limitations

  • You cannot modify the collection itself (e.g., adding or removing elements) while iterating over it using a foreach loop. Doing so will result in an InvalidOperationException.
  • If you need to modify elements of a collection, consider using a for loop or other appropriate methods that provide access to the collection by index.
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