Finding a string within a string C# with Example

Using the System.String.Contains you can find out if a particular string exists within a string. The method returns 
a boolean, true if the string exists else false. 
string s = "Hello World"; 
bool stringExists = s.Contains("ello"); //stringExists =true as the string contains the substring 
Using the System.String.IndexOf method, you can locate the starting position of a substring within an existing 
string. 
Note the returned position is zero-based, a value of -1 is returned if the substring is not found. 
string s = "Hello World"; 
int location = s.IndexOf("ello"); // location = 1 
To find the first location from the end of a string, use the System.String.LastIndexOf method: 
string s = "Hello World"; 
int location = s.LastIndexOf("l"); // location = 9