November 3, 2017 VS three broad classes & Arrays &VS& collections & Generic Collections

Three major categories

It is divided into two major categories:

Basic data type & reference type

Basic data type---value type---integral type---commonly used integers: Int, long integer: Long, small integer: Byle, medium integer short

--floating point--small floating point: float, medium floating point: Double large floating point: Declaml

--Boolean--bool (wrong type)--ture| | False

--Character Type-char (single character)

Reference types--strings--string

--Time Date--DateTime

Array

Type must be specified and length must be specified

Int[] A = new int[Tim length];

Int[] B = new int[]{add number};

String[] D = new string[]{"Double quotes with numbers, separated by commas, and a double quote can only be counted as one"};

Of course, not only the int type can be, other can also

Array traversal

Console.WriteLine (add index value inside b[]);

Console.read ();

foreach (int c in b) {

Console.WriteLine (c);

Array sorting

}

Array Assignment

a[index value] = number (because it is of type int);

Two-dimensional arrays

int[,] e = new int[1,1];

int[,] e1 = new int[,]{{},{},{}};

Two-dimensional array values

Console.WriteLine (e1[0,2])//Take two values from the 0th one

Bubble sort

 int[] A =New int[] {9,5,8,4,2,1 };  for(inti =0; I < a.length-1; i++)            {                 for(intIB = i +1; IB < A.length; ib++)                {                    if(A[i] >A[ib]) {                        inth =A[i]; A[i]=A[ib]; A[IB]=h; }                }            }            foreach(intKincha) {Console.WriteLine (k); } console.read ();

Collection

No need to specify type and length

Outside to add: using System.Collections;

ArrayList arr =NewArrayList (); DateTime DT=NewDateTime ( ., One,3);
Add arr. ADD ("ABC"); Arr. ADD (123); Arr. ADD (true); Arr.            ADD (DT); //Collection Traversal//foreach (var x in arr)//{            //Console.WriteLine (x); //}            //arr.            Remove (123); //arr.            RemoveAt (1); //arr. Reverse ();//Sequential RolloverArr. Insert (2,"AC"); Console.WriteLine (arr. Contains (123)); //foreach (var x in arr)//{            //Console.WriteLine (x); //}Console.read ();

Generic collection

Not specified length specified type

//class to be on the same lateral as the static void Main (string[] args)classuser{PUBILCintuser_id; PUBILCstringuser_name;}
New Linst<user> i =NewLinst<user>();
Insert User SJ=Newuser (); sj.user_id=1; Sj.user_name="Zhang San"; I.add (SJ); user LS=Newuser (); ls.user_id=2; Ls.user_name="John Doe"; I.add (LS);foreach(User Xinchi) {Console.WriteLine (x.user_id);}

list< type or class table name > i = new list< type or class's Table name > ();

Add to

I.add (e.g. 123);

Regular expressions

 stringstr ="\""; stringtemp =Console.ReadLine (); Regex Rx=NewRegex ("\\d"); if(Rx. IsMatch (temp)) {Console.WriteLine ("non-negative integers"); }Else{Console.WriteLine ("is not"); }

Array

            Try             {                intint. Parse (temp);                Console.WriteLine (" is number ");            }             Catch             {                Console.WriteLine (" you are not entering a number ");            }            Console.WriteLine (x);

November 3, 2017 VS three broad classes & Arrays &VS& collections & Generic Collections