string HelloWorld = "Hello World";
HelloWorld.StartsWith("Hello"); // true
HelloWorld.StartsWith("Foo"); // false

Finding a string within a string

Using the [System.String.Contains](<https://msdn.microsoft.com/en-us/library/dy85x1sa(v=vs.110).aspx>) 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