C # common collection classes

C # common collection classes

Collection)

ArrayList:

Using System; using System. collections. generic; using System. text; using System. collections; namespace SpaceName {class Program {static void Main (string [] args) {ArrayList array = newArrayList (); array. add (100); // Add an object {100} foreach (int number in new int [6] {9, 3, 7, 2, 4, 8}) {array. add (number); // Add multiple objects array = {100, 9, 3, 7, 2, 4, 8} int [] number2 = new int [2] {11,12}; array. addRange (nu Mber2); // Add an array object array = {100, 9, 3, 7, 2, 4, 12} array. remove (3); // Remove array = {100, 9, 4, 12} array with a value of 3. removeAt (3); // remove 3rd arrays = {100, 9, 12} ArrayList array2 = new ArrayList (array. getRange (1, 3); // The New ArrayList takes only a portion of the old ArrayList. array2 = {9, 7, 4,} Console. writeLine ("Traversal method 1:"); foreach (int I in array) // do not forcibly convert {Console. writeLine (I); // Traversal method 1} Console. writeLine ("Traversal method 2:"); for (in T I = 0; I! = Array2.Count; I ++) // The array is length {int number = (int) array2 [I]; // The Console must be forcibly converted. writeLine (number); // Traversal method 2 }}}}

Stack class andQueueClass:

System.Collections.Stack stack=new System.Collections.Stack();stack.Push(1);stack.Push(2);stack.Push(3);stack.Push(4);stack.Push(5);while(stack.Count>0){System.Console.WriteLine(stack.Pop());}

System.Collections.Queue queue=new System.Collections.Queue();queue.Enqueue(1);queue.Enqueue(2);queue.Enqueue(3);queue.Enqueue(4);queue.Enqueue(5);while(queue.Count>0){System.Console.WriteLine(queue.Dequeue());}

 Dictionary

Dictionary <string, string> myDic = new Dictionary <string, string> (); myDic. add ("aaa", "111"); myDic. add ("bbb", "222"); myDic. add ("ccc", "333"); myDic. add ("ddd", "444"); // if an existing key is added, the add method throws an exception. try {myDic. add ("ddd", "ddd");} catch (ArgumentException ex) {Console. writeLine ("this key already exists:" + ex. message);} // The ContainsKey () method is used to determine whether the key exists if (! MyDic. containsKey ("ddd") {myDic. add ("ddd", "ddd");} else {Console. writeLine ("this key already exists:");} // when the index is used for negative values, if the key already exists, the key value of the existing key is modified, and does not throw an exception. myDic ["ddd"] = "ddd"; myDic ["eee"] = "555"; // when the indexer is used for value, if the key does not exist, an exception will be thrown. try {Console. writeLine ("nonexistent key" "fff" "has the key value:" + myDic ["fff"]);} catch (KeyNotFoundException ex) {Console. writeLine ("the key is not found and an exception is thrown:" + ex. message) ;}// you can use ContarnsKey () to determine whether a key exists, if you often need to calculate the key value, it is best to use the TryGetValue method to obtain the corresponding key value in the Set string value = ""; if (myDic. tryGetValue ("fff", out value) {Console. writeLine ("nonexistent key" "fff" "key value:" + value);} else {Console. writeLine ("the corresponding key value is not found");} // The following uses foreach to traverse the key-Value Pair // generic struct to store the key-Value Pair foreach (KeyValuePair <string, string> kvp in myDic) {Console. writeLine ("key = {0}, value = {1}", kvp. key, kvp. value);} // obtain the Value set foreach (string s in myDic. values) {Console. writeLine ("value = {0}", s) ;}// obtain a Dictionary <string, string>. valueCollection values = myDic. values; foreach (string s in values) {Console. writeLine ("value = {0}", s );}

HashTable:

 List

List <string> names = new List <string> (); names. add ("Qin Yu"); names. add ("ye Chen"); names. add ("ye fan"); // traverse Listforeach (string name in names) {Console. writeLine (name);} // Insert the element names to the List. insert (2, "Lin Dong"); // remove the specified element names. remove ("ye fan ");

Although the knowledge is relatively basic, it still gives a lot of inspiration to myself. learning is a process of constant contact, and then gradually deepen understanding, instead of being a fat man.