Tag:Return value

  • C ා entrusted supplement 01


    In the last article, we wrote some basic things about entrustment. In this article, we talked about other things about entrustment. Example 1 plug in programming According to the understanding of delegates, delegates can pass a method as a parameter. With this feature, we can use delegates to implement plug-in programming. public delegate int Transformer(int […]

  • Covariant and contravariant


    Forward: https://www.cnblogs.com/ninputer/archive/2008/11/22/generic_covariant.html Background: covariance and contraversion   Suppose there are two types: Tsub is a subclass of tParent. Obviously, Tsub type references can be safely converted to tParent type references. If a generic interface ifoo,IFooCan be converted to ifooIn other words, we call this process covariant, and say that this generic interface supports covariance for t. […]

  • Ted:1 Vulnhub Walkthrough


      Host level port scanning: ╰─ nmap -p1-65535 -sV -A Starting Nmap 7.70 ( https://nmap.org ) at 2019-08-09 11:11 CSTNmap scan report for is up (0.00075s latency).Not shown: 65534 closed portsPORT STATE SERVICE VERSION80/tcp open http Apache httpd 2.4.18 ((Ubuntu))|_http-server-header: Apache/2.4.18 (Ubuntu)|_http-title: LoginMAC Address: 00:0C:29:E3:43:B0 (VMware)Device type: general purposeRunning: Linux 3.X|4.XOS CPE: cpe:/o:linux:linux_kernel:3 […]

  • waiting_520


    As a programmer, you must have encountered NullPointerException, which is inevitable for new comers or experienced people in the Jianghu, but it is so powerless. In order to solve it, you can only judge a value before using it. However, this will make the code become bloated. Fortunately, jdk8 introduces optional to deal with the […]

  • Basic use and source code analysis of promisekit


    Promise is an application framework that deals with a series of asynchronous operations. It can ensure that a series of asynchronous operations can be executed in sequence. When an error occurs, it can be handled by catching the error. Promise framework is also a good interpretation of Swift’s face-to-face protocol programming and functional programming There […]

  • Implement asynchronous non blocking IO development by using swoole and PHP


    “When encountering a block, the scheduler can interrupt the active transfer of resources, and choose other processes to run. To achieve non blocking IO “ However, PHP does not support native processes. When encountering a block, it is meaningless to leave the asynchronous process to execute. The code is executed synchronously, as follows: function foo() […]

  • Vuex (Vue state management)


  • Using skill of return value of InputBox function in vbs


    If the user clicks OK or presses enter, the InputBox function returns the contents of the text box. If the user clicks cancel, the function returns a zero length string (”). This is a simple and clear description of the return value of the InputBox function in the reference manual. It is also necessary to […]

  • Functions of file editing in C language


    Fopen() function Function function To open a file Header file #include usage FILE *fopen(char *filename, *type); TYPES “r”——only read “w”——only write “A” – create a file when there is no file “R +” — readable and writable “W +” — readable and writable “A +” — initialization at the beginning of the file, attached to […]

  • C basic syntax


    Semicolon; In C program, division is the statement terminator. Each statement must end with division, which indicates the end of a logical entity For example: printf(“Hello, World! \n”); return 0; Notes //Single line notes /*Single line notes*/ /* multiline comment multiline comment */ identifier The C identifier is the name used to identify a variable, […]

  • Functions of the introductory course of go language (10)


    Hello, everyone. I’m xiaozhanjun. The vacation is over in a blink of an eye. I don’t know if you have a good time? Last time we talked about the process control of go language, xiaotanjun also hopes that his friends will follow him step by step to tap the code and make progress with each […]

  • Introduction to go language (XI)


    Original: it dry warehouse Hello, everyone, I’m xiaotanjun. I talked about the definition of go language function and some kinds of self-defined function yesterday. We will continue to share what we said in the last issue today. 1. Return value of function without parameter Functions with return values must have explicit termination statements, otherwise compilation […]