c# fundamentals book

initial value set, the compiler automatically generates a default static constructor. The default initial value of a global variable for a simple value type is 0 because the entry function is in class B, so the program first loads B, and because Y is a static member of B, the value of Y is computed when the class is loaded, but the value of Y is found to be obtained by assigning a value, and the value of x is immediately computed. X is initialized by the static constructor of Class A, and refe

elements is sufficient, but the program sometimes needs to process 200 elements. For security purposes, an array containing 200 elements is used. In this way, the program wastes memory in most cases. OOP makes the program more flexible by deferring such decisions to the run stage. After the program runs, you can tell it requires only 20 elements, and you can tell it requires 205 elements next time.In summary, when using OOP, the programmer may determine the length of the array at run time. To u

Pure virtual function and abstract class of C + + FoundationIntroductionThe position of pure virtual function in C + + programming is very important, it is related to the concept of "interface" in design pattern.GrammarSyntax for pure virtual functions:1. Declare the member function as virtual2, after adding = 03. The function does not have a function body1 Class 2 {3 virtual0; 4 ... .. 5 };F

The difference between ref and out is that in C #, parameters can be passed either by value or by reference. Passing parameters by reference allows a function member to change the value of a parameter and keep the change. To pass parameters by reference, you can use the ref or out keyword. The two keywords, ref and out, can provide similar effects and act like pointer variables in C. The difference between

class is declared, there is no two semantic problem that occurs when multiple inheritance takes place on the same base class, and provides a unique base class member for the farthest derived class without producing multiple copies. It is important to note that the common base class is designed as a virtual base class at the first level of inheritance.Virtual base class and its derived class constructors The class you specify when you create an object is called the furthest derived clas

final program displays the contents of the snack variable. the the the voidShowsnack () - { inCandyBar snack = {"Mocha Munch",2.3f, - }; thecout " "" "Endl; the } About the //3. Write a program that allows the user to enter three times 50-meter run results, display times and average scores. Use the Array object to store the data. the voidRundata () the { + //Totalrun Totalrun; - //cout the //cin >> totalrun.run1;Bayi //cout the //cin >> totalrun.run2; the //cout

" - "2433359459423431413413";//No need to add any symbols in the middle -cout Endl; in - Charname[ -]; to Charfood[ +]; +cout "your name is:"; - //when using CIN to receive input, it is separated by blanks (spaces, carriage returns, tabs) . the //If there are spaces in the name, an error occurs. The solution is to use Cin.getline () to read a line. * //CIN >> name; $Cin.getline (Name, -);Panax Notoginsengcout "The foods you like are:"; -CIN >>Food ; thecout "like t

1 //22-Combination assignment operator and relational operator. CPP: The entry point that defines the console application. 2 //3 4#include"stdafx.h"5#include 6#include 7#include 8#include string>9 using namespacestd;Ten One intMain () A { - // + - * / - //+ = = *=/=%= combination assignment operator the intA = at, B = in; -A + = B;//a=a+b; -cout Endl; -A-=b; +cout Endl; -a*=b; +cout Endl; AA/=b; atcout Endl; -A%=b; -cout Endl; - - //> >= - BOOLres = the> the; incout Endl;

; isizeof(b)/sizeof(Student); i++) - { Wu b[i].show (); - } AboutCin.Get(); $}View CodeUnfortunately, the program can not be compiled successfully, why?Because: the class is an abstract concept, not an entity, and cannot contain attribute values (here is the argument of the constructor), only the object occupies a certain amount of memory space, contains a definite attribute value!See: Http://pcedu.pconline.com.cn/empolder/gj/c/0

, adjusting spacing, and so on.The order of the controls can be set at design time by selecting the controls you want to set, selecting the order under the format, and then clicking the put to bottom (or top-level) command to set.The control's alignment action is designed with the SHIFT or CTRL feature to select multiple controls, select the Alignment command under formatting, and pop up the alignment menu. Choose the alignment that applies to you.Using VS2012 is relatively easy, and the basic o

"-prov"MyProvider":: Export aspnet_regiis-px"MyKeys" "D:/mykeys.xml"-pri:: Delete key container Aspnet_regiis-pz"MyKeys" Pause @echo ONCD C:\Windows\Microsoft.NET\Framework\v2. 0.50727 :: delete old key container aspnet_regiis -pz " mykeys " : Import new key container aspnet_regiis -pi " mykeys " " d:/mykeys.xml " :: Set access permissions for an application pool aspnet_regiis -pa " mykeys " " Span style= "COLOR: #800000" >iis apppool

not use the class's member variables, then it can be successful, if the call function uses the class member variable, then it will crash, if the virtual function is called, there will be problems, because the virtual function is accompanied by the instantiation of the resulting. There is no virtual function table without instantiation.Can a static member function also be a virtual function?No, call a static member function without an instance. But calling a virtual function requires a pointer t

(enemy1.name); Print (ENEMY1.HP); Enemy1.name = "Mary"; Print (enemy1.name); Enemy enemy2 = new Enemy (); Enemy2.name = "small Two"; Print (Enemy1.name + "-" + enemy2.name); Enemy1. Move (); Enemy2. Move (); }} The field of class Enemy {public string name;//public can access public int hp through the object ; public void Move () { Debug.Log (name + "Moving"); } public void Attack () { Debug.Log ("attacking")

The thought and program realization of exception handlingThe basic idea of exception handlingSyntax for exception handlingException Interface Declaration A function explicitly declares an exception that may be thrown, which facilitates the caller of the function to prepare for exception handling You can list all the exception types that the function might throw in the declaration of the function. For example: void Fun () throw (a,b,c,

1 //17-pointers and arrays. CPP: The entry point that defines the console application. 2 //3 4#include"stdafx.h"5#include 6#include 7 8 using namespacestd;9 Ten intMain () One { A inta[]{345, $, at,7,2,856, at, the,176}; -cout //Output array is also output a string of addresses, the output address is the first element of the array address. Arrays are also pointers in C + +. - //If array A is a pointer, you can view the value of the pointer w

return a DataReader object that can read multiple records from the database by DataReader.DataReader ObjectAdo. NET DataReader objects can retrieve read-only, forward-only streams of data from the data source, extracting only one record from the data source at a time. Using DataReader can improve the performance of your application and reduce system overhead. DataReader belongs to a. NET data provider, and each. NET data provider has a corresponding DataReader class.. NET data provider and its

Static memory allocation and dynamic memory allocation in C + +:1. The static object is a variable with a name, we manipulate it directly, and the dynamic object is a variable with no NameWe manipulate it indirectly through pointers. (Static memory allocation is because when the source code is compiled, the compiler allocates memory space for the variable instead of allocating memory when the program executes, and dynamic memory allocation allocates m

CollectionCan be seen as an arrayCreate an array of length 10Array length is 10, to insert new data, you have to re-create the array sortFixed length, not too flexibleUse collections to easily solve these problemsYou can see the set as "variable-length, array with many methods"usingSystem;usingSystem.Collections.Generic;usingSystem.Linq;usingSystem.Text;usingSystem.Threading.Tasks;usingSystem.Collections;namespacethe various methods of _07arraylist {classProgram {Static voidMain (string[] args)

, please enter the correct number of items, press ENTER to continue"); Console.ReadLine (); } Else{Console.Write ("Please enter the new data:"); intNewnum =int. Parse (Console.ReadLine ()); Nums[n-1] =Newnum; } } } Else if(Input = =4) { for(inti =1; I 1; i++) { for(intj = i +1; J )

Public Delegate voiddeltest (); classProgram {Static voidMain (string[] args) {Deltest del=T1; Del+=T2; Del+=T3; Del+=T4; Del-=T3; Del-=T1; Del (); Console.readkey (); } Public Static voidT1 () {Console.WriteLine ("I'm T1 ."); } Public Static voidT2 () {Console.WriteLine ("I'm T2 ."); } Public Static voidT3 () {Console.WriteLine ("I'm T3 ."); } Public Static voidT4 () {Console.WriteLine ("I'm T4 ."); } }C