Asp.net C # array traversal, sorting, element deletion, insertion, and random element

Asp tutorial. net c # array traversal, sorting, deleting elements, inserting, and random elements
Array Traversal

Short [] sts = {0, 100,200 };
For (int I = 0; I <sts. lenght; I ++)
{
If (sts [I]> 50)
{
.....
}
}

Random array elements

Public hashtable noorder (int count)
{
Arraylist mylist = new arraylist ();
Hashtable hash = new hashtable ();
Random r = new random ();
For (int I = 0; I <count; I ++)
{
Mylist. add (I );
}
Int listcount = mylist. count;
For (int I = 0; I <listcount; I ++)
{
Int rand = r. next (mylist. count );
Hash. add (mylist [rand], I );
Mylist. removeat (rand );
}
Return hash;
}

 

View an array operation class

Using system;
Using system. collections. generic;
Using system. text;
Using system. text. regularexpressions;
Using system. windows. forms;
Namespace arr
{
/*
* Functions:
* Add a value to the array. You do not need to manually expand the array size.
* Add two Arrays
* Remove the specified items in the array.
* Remove repeated items in the array (either a number or a string. There are two types of algorithms for strings. You can compare them by yourself)
* Remove some of the same items from the array, which is not commonly used. It was previously written as needed and has been useless for a long time.
* Re-sort the Array (the number array can be from big to small or from small to big, and only the numbers and string arrays are sorted in descending order)
* Get the most repeated items in the array. Only the string array is used. If you need a number array, you can add it yourself. The algorithm is the same.
* Pstutorial: I am not an old fan of c #. If there is any mistake in the algorithm, please forgive me.
* Communication qq: 9729052
*/
Class array
{
# Region add a value to the array
Public static string [] arrayadditem (string [] arr, string item)
{
String [] _ arr = new string [arr. length + 1];
Arr. copyto (_ arr, 0 );
_ Arr [arr. length] = item;
Return _ arr;
}

Public static string [] [] arrayadditem (string [] [] motherarray, string [] arr)
{
String [] [] _ arr = new string [motherarray. length + 1] [];
Motherarray. copyto (_ arr, 0 );
_ Arr [motherarray. length] = arr;
Return _ arr;
}
# Endregion

# Region remove the specified items in the array
/// <Summary>
/// Remove the specified items in the array
/// </Summary>
/// <Param name = "arr"> A String Array </param>
/// <Param name = "index"> index item </param>
/// <Returns> </returns>
Public static string [] removeat (string [] arr, int index)
{
If (index> = arr. length | index <0)
{
Return arr;
}
Else
{
String [] newarr = new string [arr. length-1];
Array. copy (arr, 0, newarr, 0, index );
Array. copy (arr, index + 1, newarr, index, newarr. length-index );
Return newarr;
}
}

/// <Summary>
/// Remove the specified items in the array
/// </Summary>
/// <Param name = "arr"> an array of numbers </param>
/// <Param name = "index"> index item </param>
/// <Returns> </returns>
Public static int [] removeat (int [] arr, int index)
{
If (index> = arr. length | index <0)
{
Return arr;
}
Else
{
Int [] newarr = new int [arr. length-1];
Array. copy (arr, 0, newarr, 0, index );
Array. copy (arr, index + 1, newarr, index, newarr. length-index );
Return newarr;
}
}
# Endregion

# Adding region Arrays
/// <Summary>
/// Add an array
/// </Summary>
/// <Param name = "arrays"> a two-dimensional array composed of one-dimensional arrays </param>
/// <Returns> </returns>
Public static string [] arrayadd (string [] [] arrays)
{
/* Example:
* String [] array1 = {};
* String [] array2 = {"1", "2", "3 "};
* String [] array3 = {"AB", "cd", "ef "};
* String [] [] arrays = {array1, array2, array3 };
* String [] newarray = array. arrayadd (arrays );
*/
Int itemsnumber = 0;
For (int I = 0; I <arrays. length; I ++)
{
If (arrays [I] = null)
Continue;
Else
Itemsnumber + = arrays [I]. length;
}
Int enditemnumber = 0;

String [] newarray = new string [itemsnumber];

For (int I = 0; I <arrays. length; I ++)
{
If (arrays [I]! = Null)
{
Arrays [I]. copyto (newarray, enditemnumber );
Enditemnumber + = arrays [I]. length;
}
}

Return newarray;
}

Public static int [] arrayadd (int [] [] arrays)
{
Int itemsnumber = 0;
// System. windows. forms. messagebox. show (arrays. length + ": Click Here ");
For (int I = 0; I <arrays. length; I ++)
{
If (arrays [I] = null)
Continue;
Else
Itemsnumber + = arrays [I]. length;
}
Int enditemnumber = 0;

Int [] newarray = new int [itemsnumber];

For (int I = 0; I <arrays. length; I ++)
{
If (arrays [I]! = Null)
{
Arrays [I]. copyto (newarray, enditemnumber );
Enditemnumber + = arrays [I]. length;
}
}

Return newarray;
}
# Endregion

For example:

String aa = "12, 13, 16"; so how to make it one by one insert database tutorial? The idea is as follows:
String [] comids = aa. split (',');
Foreach (string id in comids)
{
If (id! = "")
{
Txtsqlinsert + = "insert into comidlist (uemail, comids, sendtime) values ('" descrithis.txt mail. value + "', '" + id + "', default )";
}
}
Dbcon. upconnection (txtsqlinsert); // This is a function that is commonly used to input an SQL statement.

/// <Summary>
/// Execute SQL statements and return nothing
/// </Summary>
/// <Param name = "sqlstr"> </param>
Public static void upconnection (string sqlstr)
{
Sqlconnection con = new sqlconnection (constr );

Sqlcommand cmd = new sqlcommand (sqlstr, con );
Con. open ();
Cmd.exe cutenonquery (); // execute the t-SQL statement and return the number of affected rows.
Con. close ();
}