C # Determines whether a substring contains a substring that can be used directly using the CONTAINS () method

1. It is customary to use IndexOf () when judging whether a string contains another substring;

string str = "[email protected]", if (str. IndexOf ("@") >=0) {    //any other code}

2. It was later found that the contains () method was also defined in C #, using the following:

String ABC = "[Email protected]@"; bool result = ABC. Contains ("@");            

Methods similar to contains () are also defined in the collection, such as:

List, Set, and array of Contains (),

Dictionary's ContainsKey () and Containsvalue ()

　　

C # Determines whether a substring contains a substring that can be used directly using the CONTAINS () method