• Summary of JavaScript common array methods


    Add / remove elements push() Add element at the end of array let arr = [‘javascript’, ‘css’]; alert( arr.push(‘html’) );// 3 alert( arr );// javascript, css, html pop() Remove and return the last element of the array let arr = [‘javascript’, ‘css’]; alert( arr.pop() );// css alert( arr );// javascript unshift() Add an element at […]

  • Some new grammars of c#7


    1. Out parameter #region 1. Out parameter var str = “2”; ///Previous writing { int iValue; //Convert STR to int type. If the conversion is successful, assign the value to Ivalue and return true; If the conversion fails, false is returned. if (int.TryParse(str, out iValue)) { WriteLine(iValue); } } //Writing method of c#7 { if […]

  • Code collaboration in code review


    Introduction: there is also “talk is soap. show me the code” in code review. When the language is weak, go to the code directly. This is the topic we are going to discuss today – Code collaboration in code review. Author | ZhiyouSource | Alibaba technology official account The great God said, “show me the […]

  • Parsing of the five most anticipated new features of JavaScript ES2021


    At the time of writing, the new JavaScript proposal functionality mentioned in this article has entered phase 4 and will almost certainly be included in ES2021. You can start with the latest version of browser, node JS and Babel. Note: ECMAScript is the standard on which JavaScript is based and is managed by TC39 Committee. […]

  • SQL Server batch import big data


    In the past, usually, the method of inserting multiple pieces of data into the database at one time is to insert them one by one with circular code. This method is inefficient in the face of millions or tens of millions of levels of data, and it usually takes a few minutes, or even dozens […]

  • [good luck eating bags tonight] 003 – decamelize


    brief introduction Convert a camelized string into a lowercased one with a custom separator. Look at the profile, we knowdecamelizeThis package is mainly used to separate strings. Official example: const decamelize = require(‘decamelize’); decamelize(‘unicornRainbow’); //=> ‘unicorn_rainbow’ decamelize(‘unicornRainbow’, ‘-‘); //=> ‘unicorn-rainbow’ directory structure Omitted. Main code ‘use strict’; const xRegExp = require(‘xregexp’); /** *@param {string} text […]

  • Hive of big data technology chapter 3 hive data types basic data types and collection data types


    Chapter 3 hive data types 3.1 basic data type Hive data type Java data type length example TINYINT byte 1byte signed integer 20 SMALINT short 2byte signed integer 20 INT int 4byte signed integer 20 BIGINT long 8byte signed integer 20 BOOLEAN boolean Boolean type, true or false TRUE FALSE FLOAT float Single-precision floating-point 3.14159 […]

  • MySQL creates stored procedures and uses events to call them regularly


    1、 To create a stored procedure using the command line: parameter details reference https://www.mysqlzh.com/ 1. Template Delimiter $$\\set the delimiter to ‘$$’, and the default statement delimiter for MySQL is’; ‘, In this way, the subsequent code from create to end will be executed as a statement Create procedure stored procedure name (your parameter is […]

  • Python string str


    Python string str Class definition Object to string Str (object = ”) returns object__ str__ () or repr (object) Byte to string str(bytes_or_buffer, encoding=sys.getdefaultencoding() , errors=’strict’) Encoding encoding conversion sys.getdefaultencoding() := ‘utf-8’ Errors error handling ‘strict’ – UnicodeEncodeError Exception ‘ignore’ – ignore errors, skip and do not process ‘replace ‘- replace with’ (‘\ ufff’) in […]

  • Three swordsmen | awk


    I didn’t understand at firstawkLater, I looked at the senior brother’s code and knocked it every day, which improved a little. Elder martial brother2020-07-03 data processing of common interesting commandsSummarizes a lot of code, very useful!I often can’t remember. I’ll go in and copy it when I use it. Here are some simple basic usages. […]

  • ASCII control character table


    Char # digraph # hex # Dec # official name # explain escape character^@Nu # 0x00 # 0 # null (nul) null character \ 0^A # sh # 0x01 # 1 # start of heading (soh)^B # SX # 0x02 # 2 # start of text (STX)^C # ex # 0x03 # 3 # end […]

  • Introduction to Linux basic commands 8: text analysis awk


    awkIt is a pattern scanning and processing language. It is a very powerful tool for data analysis and processing. awk [options] ‘pattern {action}’ file… awkThe working process is as follows: read the input by line (standard input or file), for compliance modepatternLine, executionaction。 WhenpatternIf omitted, it means to match any string; WhenactionOmission indicates execution'{print}’; They […]