• A brief tutorial on Scala


    Reading instructions This tutorial is for developers with some programming experience. This tutorial is expected to take 30 minutes Language description Scala is developed based on Java, combining object-oriented programming technology and functional programming technology. Scala’s static type avoids most of the bugs in complex programs. Its JVM and JS runtime environment allows you to […]

  • Binary heap sequential storage


    Implementation of binary heap by array Create three files: heaprarray. H, heaprarray. C, heapararraytest. C heapArray.h #ifndef HEAP_ARRAY_H_ #define HEAP_ARRAY_H_ #ifdef __GNUC__ #define DEPRECATED __attribute__( (deprecated) ) #elif defined(_MSC_VER) #define DEPRECATED __declspec( deprecated ) #else #define DEPRECATED #endif #ifndef PTOI #define PTOI( p ) ((int32_t)(int64_t)(p)) #endif #ifndef ITOP #define ITOP( i ) ((void *)(int64_t)(i)) #endif […]

  • JS regular expression syntax


    regular expression syntax Regular expression is a text pattern composed of ordinary characters (such as numbers, letters, punctuation and metacharacters used to represent a specific character or character set) and special characters (characters used as qualifications or special functions). Common characters All numbers, lowercase letters, uppercase letters, punctuation are common characters. Metacharacters are required to […]

  • Stack chain storage


    Linked list implementation stack Create three files: stacklinked. H, stacklinked. C, stacklinkedtest. C stackLinked.h #ifndef STACK_LINKED_H_ #define STACK_LINKED_H_ #ifdef __GNUC__ #define DEPRECATED __attribute__( (deprecated) ) #elif defined(_MSC_VER) #define DEPRECATED __declspec( deprecated ) #else #define DEPRECATED #endif #ifndef PTOI #define PTOI( p ) ((int32_t)(int64_t)(p)) #endif #ifndef ITOP #define ITOP( i ) ((void *)(int64_t)(i)) #endif #define ADT […]

  • Queue chain storage


    Linked list realizes queue Create three files: queuelinked. H, queuelinked. C, queuelinkedtest. C queueLinked.h #ifndef QUEUE_LINKED_H_ #define QUEUE_LINKED_H_ #ifdef __GNUC__ #define DEPRECATED __attribute__( (deprecated) ) #elif defined(_MSC_VER) #define DEPRECATED __declspec( deprecated ) #else #define DEPRECATED #endif #ifndef PTOI #define PTOI( p ) ((int32_t)(int64_t)(p)) #endif #ifndef ITOP #define ITOP( i ) ((void *)(int64_t)(i)) #endif #define ADT […]

  • About exports; module.exports ; export; export default distinguish


    1. About exports and module.exports (node is operational) When a node executes a file, an exports and module object will be generated in the file,Module has an exports attribute. exports = module.exports = {}; exports.js var frist1 = 1 module.exports = frist1 importm.js const frist1 = require(‘./exports.js’); console.log(frist1) Run: node importm.js 2. About export and […]

  • Java process control: select structure


    1、 Select structure The selection structure is used to judge the given conditions and control the program flow according to the judgment results. The syntax of choice structure in Java is mainly divided into‘if… Else’ statementand‘switch… Case ‘statement。 In Java, select structure statements can be nested at will in syntax, but it is not recommended […]

  • Resume, interview brush? Refuse your HR sister, maybe it’s just an AI


    Introduction:Nowadays, AI is becoming more and more intelligent, which makes many people worry whether they will be replaced by AI one day. In fact, so far, AI is still in the stage of weak artificial intelligence, and most human jobs cannot be replaced by AI for the time being. However, at present, AI can decide […]

  • Data analysis SQL advanced


    1 Introduction SQL advanced mainly introduces predicate, case expression, nested subquery, join (join the table by column) and union operation (table as unit). 2 SQL advanced 2.1 predicate LIKE Before introducing like, first introduce wildcard characters. MySQL only supports percent sign (%) and underline (_) , percent sign replaces 0 or more characters, and underline […]

  • New features of C + + 17


    Program meow has already introduced the new features of C + + 11 and the new features of C + + 14. The link is as follows: XXX, today, I’d like to introduce the new features of C + + 17 to our dear readers. Now basically, all compilers have provided complete support for C […]

  • Spring 5 Chinese parsing core chapter – the spice expression of IOC container


    Spring expression language (spel) is a very powerful expression language. It supports query at run time and manipulation of object graph manually. The language syntax is similar to El, but provides additional features, most notably method calls and basic string template functionality. There are several other Java expression languagesOGNL、MVELandJBoss ELYes, but the spring expression language […]

  • SQL case statements and decode functions


    Database table: select * from rec order by rst,game_time; ID GAME_TIME RST 2 January – January – 11 F 6 January – January – 11 F 3 February – January – 11 F 9 February – January – 11 F 7 March – January – 11 F 1 January – January – 11 W 4 […]