Tag：scope
-
Time：2021-12-30
Original link:Understanding lifetimes in Rust Today is a good day. You want to try rust programming again. The last attempt was very smooth, except for a littleBorrowing checkBut in the process of solving the problem, you understand its working mechanism, and everything is worth it! Borrowing check can’t stop your rust grand plan. After conquering […]
-
Time：2021-12-28
Modular development is one of the most important front-end development paradigms Modular evolution process Stage1 file division methodThe specific method is to put each function and its related status data into different files separately. It is agreed that each file is an independent module. Using a module is to introduce the module into the page, […]
-
Time：2021-12-28
Namespace Namespaces: used to store the binding relationship between name and memory address. It is the division of stack area Function: the namespace can store the same name in the stack area, so as to solve the naming conflict There are three types of namespaces: Built in namespace Global namespace Local namespace Built in namespace […]
-
Time：2021-12-26
@ catalogue HTML 1. How to understand HTML semantics 2. By default, which HTML tags are block level elements and which are inline elements 3. HTML5 new content and API CSS 1. Box model 2. Margin vertical overlap 3. Margin negative value 4. BFC (block level formatting context) 5. Float layout 6. Flex layout 7. […]
-
Time：2021-12-24
In our daily work, we often useerr != nilTo determine whether the program or function reports an error, or usedefer {recover = err}To determine whether there ispanicSerious error, but if you don’t pay attention, it’s easy to fall intoerr shadowA trap. 1. Variable scope package main import “fmt” func main() { x := 100 func() […]
-
Time：2021-12-23
Scope RubyIt does not have the characteristics of nested scopes (that is, in the internal scope, you can see the external scope). Its scopes are completely separated. Once you enter a new scope, the original binding will be replaced by a new set of bindings. The program will close the previous scope in three places […]
-
Time：2021-12-19
Write in front This series comes from open source projects:Front end 100 Q: if you can understand 80%, please give me your resumeIn preparation for the 2021 spring moveAsk one question every day and urge yourselfSummarize the answers from many aspects and angles to enrich knowledge What is the difference between an arrow function and […]
-
Time：2021-12-15
1、 Introduction Closure is a difficult point in JavaScript language. It is often asked in interviews, which is also its feature. Many advanced applications rely on closure. This paper tries to explain the concept, formation conditions and common interview questions of closure in simple and understandable words. Let’s take a look at an example: var […]
-
Time：2021-12-15
What is jest What does testing mean How do I know what to test Test blocks, assertions, and matchers How to implement test blocks How to implement assertion and matcher CLI and configuration simulation How to simulate a function execution environment Scope isolation V8 virtual machine Run single test callback Hook function Generate report jest-cli […]
-
Time：2021-12-13
JS Variable types and calculations typeofCan you judge which types When to use = = = when to use== Difference between value type and reference type Handwritten deep copy Value type and reference type Value types are stored in stack memory and reference types are stored in heap memory //Value type let a = 100 […]
-
Time：2021-12-8
If statement judgment The conditions in if can be assigned The scope of the variable assigned in the if condition is in this if statement if contents, err := ioutil.ReadFile(filename); err != nil { fmt.Println(err) } else { fmt.Printf(“%s\n”, contents) } //An error will be reported here. Contents scope is different // fmt.Printf(“%s\n”, contents) switch […]
-
Time：2021-12-8
design sketch Environmental preparation Prepare the docker environment, including docker compose. Here, you can directly use the docker compose configuration file. $ mkdir docker-composes $ git clone https://github.com/docker-composes/postgres.git $ git clone https://github.com/docker-composes/grafana.git $ git clone https://github.com/docker-composes/prometheus.git Note: the following operations start from the docker compositions directory. Container configuration Postgres exporter configuration vim postgres/exporter/docker-compose.yml Set the […]
