Find The Position Of The First Occurrence Of A Substring In A String In C#

Finding the position of the first occurrence of a substring in a string is a commonly required operation in programming tasks. This short article will demonstrate how you can achieve this using C#.

Code snippet to Find The Position Of The First Occurrence Of A Substring In A String

    string mainString = "Hello World Csharp Tutorial";
    string subString = "Csharp";

    int position = mainString.IndexOf(subString);

    Console.WriteLine(position);

Code Explanation For Finding The Position Of The First Occurrence Of A Substring In A String.

Let’s breakdown the code to understand it better.

1. string mainString = "Hello World Csharp Tutorial"; Here, we define a variable ‘mainString’ that holds our main string.

2. string subString = "Csharp"; Similarly, we define another string ‘subString’. This string is what we’ll be searching for in our main string.

3. int position = mainString.IndexOf(subString); The ‘IndexOf()’ function is a built-in method in C# that returns the index of the first occurrence of a specified substring. If the substring is not found, it returns -1. We pass the ‘subString’ to ‘IndexOf()’ function, called from ‘mainString’. The result (position of the first occurrence of the substring in the main string) is stored in the integer variable ‘position’.

4. Console.WriteLine(position); Finally, we print the result to the console. If ‘subString’ is found in ‘mainString’, the output will be the zero-based index of the first occurrence of the subString within the mainString. If not found, the output will be -1.

This simple yet powerful method allows you to find the position of the first occurrence of a substring within a main string in C#, thus making your coding tasks easier.