udacity introduction to programming

is the OOP programming in the late binding mechanism, to add virtual, non-OOP early bundle, the linker call function when you need to know the absolute address6, data put to the stack (automatic, local variables) and static memory speed faster, sacrificing flexibility, put into the heap can be dynamically created, actually run to know the size7, exception handling is not OOP features, appear earlier than OOP, but it is very important, can directly wi

Introduction to multi-thread programming I have been involved in multi-threaded programming in C language for the first time. I have only done java's Runnable multi-threaded programming before. This time, we can regard the screen as a resource which is shared by two threads,# Include # Include Using nam

Linux Network Programming-Introduction to elementary network functions (TCP)-Linux general technology-Linux programming and kernel information. The following is a detailed description. In Linux, network programming is implemented through socket. network programs call socket and several other functions to return a commu

current variable, and in Python we never know how much memory space a variable is currently allocating. Typically, memory space is consumed for the following reasons: 1. An uncontrolled growth of a variable; 2. There are too many instances in the global, and they do not monitor their use of memory; 3. The thread that does not shut down properly; 4. Objects with __del__ properties in a loop bodyThe specific memory detection tools are: Guppy, heapy View Network usage This part of th

" button.Psbtn_cancel Select the "CANCEL" button.PSBTN_HELP Select the Help button.() Removepage () functionDeletes a property page. The function prototypes are:void Removepage (CPropertyPage *ppage);void Removepage (int Npage);Parameter ppage: The object pointer to the property page to delete.Parameter npage: The index of the property page to delete.Properties dialog box and related two classes Chicken peck rice is introduced here, mainly for the later use of the Property Page dialog box to pre

optimal income is in the kind of cut distribution mode, such as n=9, the best yield is 25, to be divided into 3 and 62 segments. Here you can use another array s to store the segmentation situation, such as s[9] storage 3, and then we let n=9-3, we can get s[6] the best segmentation situation, found that is 6, so there is no need to continue.You only need to modify the code slightly to achieve the goal: #include Running the above program, we can get the best yield of 9 steel pipe and the corres

been sending data will cause the buffer data is full, the computer is stuck, all receivers need to receive data in time3, Summary:UDP is a simple transport-layer protocol for datagrams. UDP does not provide reliability, it simply sends the application to the IP layer's datagram, but does not guarantee that it will reach its destination. Because UDP does not have to establish a connection between the client and the server before transmitting the datagram, and there is no mechanism such as time-o

all the optimal return value RI and the corresponding optimal solution scheme:R1 = 1, cut solution 1 = 1 (no cut)R2 = 5, cut solution 2 = 2 (no cut)R3 = 8, cut solution 3 = 3 (no cut)R4 = 10, cutting scheme 4 = 2 + 2R5 = 13, cutting scheme 5 = 2 + 3R6 = 17, cut solution 6 = 6 (no cut)R7 = 18, cutting scheme 7 = 1 + 6 or 7 = 2 + 2 + 3R8 = 22, cutting scheme 8 = 2 + 6R9 = 25, cutting scheme 9 = 3 + 6R10 = 30, cut solution 10 = 10 (no cut)More generally, for RN (n >= 1), we can describe it with th

/yyyy 4 104 Dd.mm.yy 5 105 Dd-mm-yy 8 108 Hh:mi:ss 20 or 120 Yyyy-mm-dd Hh:mi::ss (24h) Example select ename+‘‘‘‘+‘s sal is‘+convert(char(7),sal) as ‘EMPLOYEE‘S SAL‘ from emp; as ‘客户ID‘,cname as ‘客户名称‘ convert(char(10),cRegisterationDate,102) as ‘注册日期‘ from customer; 最终显示的日期格式就会如2006.12.02 3. OperatorsArithmetic operators: + 、-、 *,/,% (redundancy)String operator: + (connection)Co

 Introduction to ①pl/sql Program designPL/SQL is an advanced database programming language that is specifically designed to access Oracle databases in a variety of environments. Because the language is integrated into the database server,So PL/SQL code can quickly and efficiently process dataThe SQL statements that can be used in PL-SQL are:Insert,update,delete,select ... Into,commit,rollback,savepoint.Ti

objectSt.executequery ("Select a,b,c from table"); Call the ExecuteQuery () method of the Statement object JDBC URL parameterThe JDBC URL provides a way to identify the database so that the appropriate driver can identify and establish a connection to the database. The standard format for a JDBC URL consists of three parts, separated by colons, as follows:jdbc:The meanings are as follows:The protocol in the JDBC:JDBC URL is always JDBC. Database operations(1) Add record: INSERT into table n

This article mainly introduces the Python alien invasion game programming complete realization idea, has certain reference value, the interested small partners may refer to the Python game programming alien invasion The complete realization idea, the concrete content as follows prepares the work: Download Python, For example, Anaconda3, import pygame game Pack 1. Alien Settings, alien.py, code: Import pygam

This article mainly introduces a deep understanding of the JavaScript series (17): An Introduction to object-oriented programming, this article describes the introduction, paradigm and ideas, class-based features and prototype-based, static-based, and hierarchical inheritance. For more information, see Introduction In

variable, (I understand) if the external variable definition appears after the function or in other source files, you need to use extern (preceded by int, etc.) declaration;The extern declarations of variables and functions are usually placed in a separate header file and include at the beginning of each source file;A declaration such as copy () is considered an old-fashioned declaration, and the parameter table will not be checked; ANSI c specifies that an empty parameter table must be declare

The system. threading namespace provides classes and interfaces that enable multi-threaded programming. There are three methods for creating threads: thread, threadpool, and timer. Next I will give a brief introduction to their usage methods one by one.1. threadThis may be the most complicated method, but it provides various flexible control over the thread. First, you must use its constructor to create a t

properties page of the Open button there are image index and large image index two properties, respectively, its small icon in the small icon sequence and its large icon index in the large icon sequence, here we set its icon for the large icon, and for the large icon sequence in the first one, Then directly set the large Image index property to 0, or you can select the icon by clicking on the browse button that appears after selecting the edit box for the large Image index property, which pops

maximize the use of CPU　　Disadvantages are as follows:1, the nature of the process is single-threaded, unable to use multicore, can be a program to open multiple processes, each process to open multiple threads, each process to open multiple threads, each line range open 2, the association refers to a single thread, so once the association is blocked, it will block the entire thread　　Summary of the characteristics of the process:1. Concurrency must be implemented in only one single thread2. No

1. Introduction to JavaScriptJavaScript was born in 1995 and developed by Netscape company Brandon Aichi, which mainly consists of three parts:(1). ECMAScript, defined by ECMA-262, improves core language functionality(2). Document Object Model (DOM), which provides methods and interfaces for accessing and manipulating Web page content(3). Browser object Model (BOM), which provides methods and interfaces for interacting with the browser1. Javacript Adv

located on the same server as the page containing it, or a file in any other domain. All Since the browser resolves the code in the Using the Defer property allows the script to be fully rendered in the document only to be executed again. Deferred scripts are always executed in the order in which they are specified. Use the Async property to indicate that the current script does not have to wait for other scripts or block document rendering. There is no guarantee that asynchro

memory, unlimited computing power, parallel threading execution, and the assumption that code is doomed to rot. Therefore, we must bear in mind that the "memory is not infinite", "Memory access overhead is not balanced, the access time for different storage media is an order of magnitude difference", "our program does not have a dedicated CPU", "on a single-processor computer, parallel programs can only be polled." 3rd, is the choice of the library, the library function is the implementation of