Programmer Group

1 if ( typeof v === 'undefined') { // true } if ( typeof null === 'object') { // true } 2 Number(null) //0 5 + null //5 Number(undefined) //NaN 5 + undefined //NaN 3 integers and floating points There are no integers at all at the bottom of JavaScript language. All numbers are decimals (64 ...

I. Preface WeChat public number development (1) WeChat access certification as developer WeChat public number development (2) message processing This article will implement Get access_token according to AppID and AppSecret Custom menu (create menu, query menu, delete menu) Some tips in wechat documents: access_token must be stored with at ...

Catalog   1, Standard library 1. regexp package: regular expression 2. sync package: lock and sync 2.1 sync.Mutex mutex 2.2 sync.RWMutex read / write lock 2.3 once.Do(call) 2, Use of packages 1. Custom package 2. reference package 3. Initialization of package 1, Standard library Built i ...

Parameter binding stay The fifth chapter Feign is used to implement a REST service binding without parameters. However, in the actual business, it is much more complicated than this. Different types of parameters are passed in at various locations of HTTP requests, and the returned parameters may als ...

Besu is the enterprise Ethereum product in Hyperledger, and its biggest advantage is that it is compatible with the Ethereum main network. This tutorial describes how to use Hyperledger Besu to quickly start an enterprise Ethernet network and use JSON RPC for data query and transaction submission, and how to use Truffle to develop enterprise Et ...

abstract API design principles: Controlling the granularity and number of API s Naming should follow the principle of simplicity, readability and uniformity. Prioritize API design, then code Say one more thing: In order to develop more efficiently and save the cost of writing documents, these popula ...

timed-out and no fallback This error basically occurs in the Hystrix fuse. The function of the fuse is to determine whether the service can be connected. If it is connected, it doesn't matter. If the call exceeds the time limit within the specified time, it will return an error through the fuse. Generally, you can set one of the following confi ...

In computer programming, unit testing is a software testing method, which is used to test a single unit of source code, a collection of one or more computer program modules, and related control data, use process and operation process to determine whether they are suitable for use. In short, when we are doing unit tests, we only test one code un ...

Entrance All changes are inseparable from its origin. First look at the source code to find the entry. First look at the entry of Vue router, which is defined in src/index. Vue router is based on class implementation. Class provides construction methods and some other methods. After the class is def ...

Linux global installation composer Switch the directory to the / usr/local/bin / directory cd /usr/local/bin/ Download composer in bin directory curl -sS https://getcomposer.org/installer | php View composer through composer.phar -v Change to Chinese image composer.phar config -g repo.packagist composer https://packagist.phpcompo ...