Tag:number

  • CTF SQL universal password

    Time:2020-10-1

    The following are some of my feelings when learning SQL injection. I hope it can help you. If you have any mistakes, please point out.   Types of universal password: ①select * from admin where username =”” and password = “” ②admin’ # ③’+’   ‘+’ ④0 ⑤Aaa’ = ‘   In the following select statement, […]

  • Implement a mini Redux (Basic Edition)

    Time:2020-10-1

    preface Starting from the principle of Redux, this paper realizes a simple Redux step by step. The main purpose is to understand the internal relations of redux. Before reading this article, you should know how Redux is used, and I won’t explain too much about the usage of redux. Introduction to Redux First of all, […]

  • Interactive encapsulation of IOS WebView and JS

    Time:2020-9-28

    Blog move IOS uiwebview is gradually eliminated and wkwebview becomes the mainstreamWKJSWebView(code see Section 3), RefEasyJSWebViewWe can call JS natively, or JS can call native. 1、 How to use it JS tone native Create an interaction class and define the interaction interface for JS // OC #import <Foundation/Foundation.h> #import “WKJSWebView.h” @interface JSInterface : NSObject – […]

  • PTA_ Data structure learning and experimental guidance_ Explanation_ 1-3.1 median of two ordered sequences

    Time:2020-9-28

    Advanced experiment 1-3.1 median of two ordered sequences Given that there are two equal length non descending sequence S1, S2, design function to find the median of the union of S1 and S2. The median of the ordered sequence a 0, a 1,…, a n − 1 refers to the value of a (n − […]

  • Oracle Basics – simple query exercise (1)

    Time:2020-9-27

    Practice based on the EMP table under Scott user in Oracle database Query all tables under Scott user select * from tabs; Query all information in employee table select * from emp; Query employee number, name, job, salary. select empno,ename,job,sal from emp; Check the type of employee’s job. select distinct job from emp; Query employee […]

  • JavaScript tools and functions

    Time:2020-9-27

    If articles and notes can bring you a little help or inspiration, please don’t be stingy with your praise and collection, your affirmation is the biggest driving force for me to move forward Attached note link, read more high-quality articles in the past, and give me praise and encouragement if you like https://github.com/Wscats/CV/issues/27 Add on […]

  • How to configure the core, executor and memory resources of spark task

    Time:2020-9-27

    Static allocation: OS 1 core 1gCore concurrency capability < = 5Executor am reserves 1 executor, and the remaining executor = total executor-1Memory reserves 0.07 per executorMemoryOverhead max(384M, 0.07 × spark.executor.memory)Executormemory (total m-1g (OS)) / nodes_ num-MemoryOverhead Example 1 Hardware resources: 6 nodes, 16 cores per node, 64 GB memory Each node reserves 1 core and […]

  • Why is precision lost? Teach you to understand IEEE-754!

    Time:2020-9-27

    Link to the original text: https://ssshooter.com/2020-09… The image above is from Wikipedia. IEEE-754 standard is a floating-point number standard. There are three formats: 32-bit, 64-bit, and 128 bit (the above two pictures are 32-bit and 64 bit respectively, and the structure is consistent). JavaScript uses 64 bit, which is commonly known as “double precision”. This […]

  • 20. Nginx performance optimization

    Time:2020-9-26

    AB performance test yum install httpd-tools ab -n 100 -c 100 http://127.0.0.1/ #Concurrent quantity Concurrency Level: 100 #Time spent on the whole test Time taken for tests: 0.014 seconds #Number of completed requests Complete requests: 100 #Number of failed requests Failed requests: 0 #Number of write errors Write errors: 0 #Number of non-200 response codes […]

  • Learn regularity from a JavaScript topic

    Time:2020-9-25

    This is an ordinary tutorial, but also one of my notes. The reason is that it is interesting to see another solution to a problem. At the same time, I also take some regular notes to understand it. subject My impression of this topic is:There is an array of[1,1,2,3,3,3,3,4,5,5,5,6,6]Using JSTurn it into[[1,1],2,[3,3,3],4,[5,5,5].[6,6]] There are many […]

  • Timeout problem in [PHP] socket client

    Time:2020-9-24

    Connection socket is divided into connection timeout and read timeout $sock=stream_ socket_ client(” www.google.com : 80 “, $errno, $errstr, 2); that number is the connection timeout. For example, if you connect to Google, an error will be returned in 2 seconds, so that you won’t be waiting there all the time stream_ set_ Timeout ($sock, […]

  • Implementation of markdown automatic numbering in CSS

    Time:2020-9-23

    The origin of the problem The first time I paid attention to the title number should be traced back to the time of undergraduate thesis, when I was also involved in this topic alone,WordIt has a very good featureCascade titleAfter setting the title style once, we can automatically number the title according to the set […]