Check out example codes for "c# find substring in string". It will help you in understanding the concepts better.

Code Example 1

string fullName = "John Doe";
bool nameInFullName = fullName.Contains("John");
// nameInFullName is true

Code Example 2

String phrase = "this is the ultimate string";

Console.WriteLine(phrase.Contains("this")); //returns True
Console.WriteLine(phrase.Contains("python")); //returns False

Code Example 3

string s = "hello";
char c = s[1];
// now c == 'e'

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