Tag:local variable

  • ⑦ Block related interview questions

    Time:2021-12-1

    1、 What is block? A block is an object that encapsulates a function and its execution context. For example: NSInteger num = 3; NSInteger(^block)(NSInteger) = ^NSInteger(NSInteger n){ return n*num; }; block(2); Compile the. M file with the command Lang – rewrite objc wytest. M and find that the block is compiled in this form: NSInteger […]

  • MySQL variables

    Time:2021-11-6

    Original linkhttp://zhhll.icu/2021/01/02/%E6%95%B0%E6%8D%AE%E5%BA%93/%E5%85%B3%E7%B3%BB%E5%9E%8B%E6%95%B0%E6%8D%AE%E5%BA%93/MySQL/MySQL%E5%8F%98%E9%87%8F/ MySQL variables MySQL variables are divided into system variables and user-defined variables System variable System variables include global variables and session variables View system variables #View global system variables show global variables; #Query global system variables according to criteria show global variables like ‘%%’; #Query a global system variable Select @ @ global. […]

  • MySQL custom functions

    Time:2021-11-3

    Original linkhttp://zhhll.icu/2021/01/03/%E6%95%B0%E6%8D%AE%E5%BA%93/%E5%85%B3%E7%B3%BB%E5%9E%8B%E6%95%B0%E6%8D%AE%E5%BA%93/MySQL/MySQL%E8%87%AA%E5%AE%9A%E4%B9%89%E5%87%BD%E6%95%B0/ MySQL custom functions Similar to stored procedures, functions are also a set of precompiled SQL statements. However, stored procedures can have 0 or more returns, and functions can only have one return Create function #The syntax parameter list contains two parts: parameter name and parameter type #The function body must have a return […]

  • IOS development interview only needs to know these, and the technology basically passes the customs! (block)

    Time:2021-10-5

    1、 What is block? Block   Is an object that encapsulates a function and its execution context.For example: adoptclang -rewrite-objc WYTest.m Command to compile the.mFile, found theblock Compiled into this form: amongWYTest Is the file name,blockTest Is the method name, which can be ignored. amongWYTest blockTest_block_impl_0 The structure is –block_impl The structure is blockInternal isaPointer, so its essence is alsoOC object block The […]

  • PHP variable scope (global variable & local variable) & Global & static keyword usage example analysis

    Time:2021-10-4

    This article describes the usage of PHP variable scope (Global & local variables) & Global & static keyword. Share with you for your reference, as follows: We know that variables are actually equivalent to the containers we use to store information. I believe you are quite clear about its naming rules, so I won’t repeat […]

  • What’s new in swift 5.5

    Time:2021-9-27

    Swift 5.5 is built into Xcode 13. Although the version number is only increased by 0.1, which seems to be a small version upgrade, it has brought a lot of new content. The biggest update is the introduction of a new concurrent programming method. Included in this article: http://www.cocoachina.com/art… Conditional compilation supports expressions Swiftui will […]

  • C + + foundation — pointer — the pit where the stack is removed when the pointer is returned

    Time:2021-9-8

    1. Function local variable address release pit Main () calls the test () method to return the address of a, but a is a local variable of test (). Therefore, after the call of test (), the stack space of test () is removed and the storage space of a is released. Even if the […]

  • IOS development interview only needs to know these, and the technology basically passes the customs( Block)

    Time:2021-8-28

    1、 What is block? Block   Is an object that encapsulates a function and its execution context.For example: adoptclang -rewrite-objc WYTest.m Command to compile the.mFile, found theblock Compiled into this form: amongWYTest Is the file name,blockTest Is the method name, which can be ignored. amongWYTest blockTest_block_impl_0 The structure is –block_impl The structure is blockInternal isaPointer, so its essence is alsoOC object block The […]

  • Today’s knowledge sharing: C + + variable scope

    Time:2021-8-13

    Scope is an area of the program. Generally speaking, there are three places where variables can be defined:     Variables declared inside a function or a code block are called local variables. Variables declared in the definition of function parameters are called formal parameters. Variables declared outside all functions are called global variables. We […]

  • Basic Java syntax: variables and constants

    Time:2021-8-11

    1、 Naming conventions AllVariables, constants, methods, classesAll useEnglish wordsNaming, toSee the name and know the meaning。 AllVariables and methodsAll names useSmall hump method: acronymic lowercase hump nomenclature.For example:sampleText classAll names useLarge hump method: acronymic hump nomenclature.For example:SampleText constantNaming of:All letters are capitalized with ”between words separate。For example:SAMPLE_TEXT 2、 Variable As the name suggests, a variable […]

  • New features of swift 5.5

    Time:2021-7-23

    Swift 5.5 is built into Xcode 13. Although the version number is only increased by 0.1, which seems to be a small version upgrade, it brings a lot of new content, among which the biggest update is the introduction of a new way of concurrent programming. Included in this article:http://www.cocoachina.com/art… Conditional compilation supports expressions Swiftui […]

  • Elisp 03: Variables

    Time:2021-6-11

    Last chapter:Text analysis The parser program implemented in the previous chapter, of course, is just a toy. There are several ugly places, and there is a security problem. global variable safety first. Let’s start with security. Observe the following code: (defun text-match (src dest) (setq n (length dest)) (if (< (length src) n) nil (string= […]