10. C # Basic finishing (collection)

Collection 1, reference to collection

using System.Collections; // Add Class

2. Define the collection (ArrayList or Array)

New ArrayList ();

3, add data (can put a variety of different data types, but it is best to put only one) (a) Single data

Method 1:add adds

Arr. ADD (3); arr. ADD (5); arr. ADD ("hello");

Output Result:

Console.WriteLine ("add[0]:"+arr[0//  Generates a 0-based index by adding the element's order, reading the data through the index, and outputting the result as "3"Console.WriteLine ("add[1]:" + arr[1  ]);//5console.writeline ("add[2]:"+arr[2]);//hello

Method 2:Insert inserts to move data that starts from the data shown in the index one

Arr. Insert (1); // Insert (index, inserted data)

Output Result:

Console.WriteLine ("Insert[0]"+arr[0]);//3Console.WriteLine ("Insert[1]"+ arr[1]);// -Console.WriteLine ("Insert[2]"+ arr[2]);//5Console.WriteLine ("Insert[3]"+ arr[3]);//Hello

(b) Array:

1. Append a set of data addrange

int New int [3678  };arr. AddRange (Shuzu);

Traverse:

foreach (object in arr) // because there may be more than one data in the collection, the object (base class) is used to traverse, and all types can be converted to this type {Console.WriteLine (" Traverse 1:" + O);}

2. Insert a set of data starting at the specified index Insertrange

Arr. Insertrange (2, Shuzu); // Traverse foreach (object in arr) {Console.WriteLine (" Traverse 2:" + O);}

4. Remove the data: (only the first match is removed)

(a) removing the specified data (value): Remove

Arr. Remove (+); // removing data with a value of 17 foreach (object in  arr) {Console.WriteLine ("Remove:" + O);}

(ii) Remove the element at the specified index location: RemoveAt

Arr. RemoveAt (2); Console.WriteLine ("Remove after index is [3] data:"+arr[3]);

5. Sort:

(1) Sort: Automatically in ascending order

New ArrayList ();  for (int05; i++) {arr1. ADD (int. Parse (Console.ReadLine ()));} Arr1. Sort (); foreach (object in arr1) {Console.WriteLine (" ascending sort:"+ o);}

(2) Reverse: flips the sort of collection (makes it descending)

arr1. Reverse (); foreach (object in arr1) {Console.WriteLine (" flipped reverse after descending:"+O);}

6. Properties of the collection:

Count: Returns how many elements are inside the collection

Console.WriteLine (" number of elements:" + arr1. Count);

7. Return to index IndexOf

Console.WriteLine ("Hello's index is:"+arr. IndexOf ("hello")); // returns only the index of the first occurrence Console.WriteLine ("the last occurrence where Hello is located is atindex:" + arr.) LastIndexOf ("hello")); // returns the index in which the last occurrence is found

* * Inserted array index is also arranged by a single data, such as: Insert a set of three number of arrays, will establish three indexes.

8, contains: Determine if there is an element, return bool value

Arr. Contains (1);

9. Clear the collection

Arr. Clear ();

10. C # Basic finishing (collection)