Two ways to traverse a dictionary

Dictionary <string, int> things = new dictionary <string, int> ();

Things. Add (........);

Things. Add (........);

 

 

Method 1: You can use the keys and values attributes to iterate the keys and values in the Set:

Foreach (string key in things. Keys)

{

//......

}

Or

Foreach (INT value in things. values)

{

//....

}

Method 2: You can also iterate each item in the set and use each item as a keyvaluepair <K, V> instance.

Foreach (keyvaluepair <string, int> thing in things)

{

Console. writeline ("{0 }={ 1}", thing. Key, thing. value );

}

 

In addition, the keys of dictionary <K, V> cannot be repeated. If the same key is added, an argumentexception exception is thrown.

However, there may be an application where the key acts as a commodity name or name, which is case-insensitive (should be treated as the same commodity or character), but we use it as the key

If an exception is thrown during addition, it violates our business logic concept (our names or product names are case-insensitive, that is, names with different cases should be treated as the same key)

Solution: when new dictionary is used, the icomparer <k> interface can be passed to the constructor. In the icomparer <k> interface, we can compare each name (for example, convert to lowercase and then compare ).

In this way, you can.