Chapter 2 Introduction to JavaScript basics 2
(3) Variables let and var
Previously, we learned that the var keyword is used to declare and create a variable. Generally, we use var to create global variables and let to create local variables.
Examples are as follows:
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta http-equiv="X-UA-C ...
Posted by A584537 on Thu, 17 Feb 2022 13:28:37 +0100
Eleven new features of workflow engine activiti7
catalogue
1, Activiti7 basic introduction
2, Download the demo of Activit official website to learn
2.1 enter the activiti core learning wizard page
2.2 # download the demo example of activiti core
2.3 # Activiti7 challenges
2.4 components of Activiti7
2.5 introduction to Activiti's new API
2.5.1 TaskRuntime
2.5.2 ProcessRunt ...
Posted by phpnoobguy on Wed, 16 Feb 2022 16:53:29 +0100
Java Foundation (16) - Date SimpleDateFormat CalendarDate class
catalogue
Overview of Date class
Construction method
Member method
Conversion between Date type and long type millisecond value
SimpleDateFormat class
SimpleDateFormat
Construction method
Definition of common rules for the SimpleDateFormat class
Member method
Case: calculate how many days you have been in this world.
Calendar Class
...
Posted by tonga on Sat, 12 Feb 2022 14:50:41 +0100
Multi table query
catalogue
1, Why do I need multi table query?
🐟 Which city does an employee named "Abel" work in?
2, How to implement multi table query
1. Error of Cartesian product (cross connection)
① Wrong implementation
② Cause of error
The query method of the table requires multiple conditions
① Join condition of two tables
② If a fiel ...
Posted by qazwsx on Sat, 12 Feb 2022 06:57:13 +0100
Learning new features of Java 8
1, Lambda expression
1. Basic syntax of lambda expression
java 8 introduces a new operator "- >", the arrow operator / lambda operator, and the arrow operator divides the lambda expression into two parts: Left: of lambda parameter On the right side of the list: the functions to be performed in lambda, that is, lambda ...
Posted by corruption on Thu, 10 Feb 2022 21:25:53 +0100
Swordfinger offer 5 - Search Algorithm
Number of occurrences of number 53 in ascending array
Given a non-descending array of length n and a non-negative integer k, it is required to count the number of times K occurs in the array Requirements: Spatial Complexity O(1), Time Complexity O(logn)
Ideas: dichotomy.
1.mid=array.length/2; Divided into [0,mid] [mid+1;length-1] If (array[m ...
Posted by gmccague on Tue, 08 Feb 2022 21:56:25 +0100
Web front end training notes 4
Source
video
green hand
css common attribute settings
background
Text
Alignment
display attribute
Float
Code 1
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<title>Common properties</title>
<style type="text/css"">
#div1 {
/*width: 5eepx;*/
...
Posted by ivi on Mon, 07 Feb 2022 13:59:12 +0100
mysql database: retrieving information from tables
catalogue
(1) Select all data
(2) Modify table contents
Method 1
Method 2
(3) Select a row individually
(4) Select special columns
(5) Classification line
(6) Date calculation
(7) NULL value operation
(8) Pattern matching
(1) Select all data
select * from pet;
Return:
(2) Modify table contents
Method 1
Delete first
DELETE FR ...
Posted by Xeon on Sat, 05 Feb 2022 20:01:03 +0100
4 integrity constraint naming clause 5.6 assertion
5.4 integrity constraint naming clause
Integrity constraint naming clause Constraint < integrity constraint name > < integrity constraint > ◾ < integrity constraints > include not null, unique, primary key phrase, foreign key phrase, check phrase, etc [example 5.1] establish a Student registration fo ...
Posted by iceraider on Fri, 04 Feb 2022 10:52:20 +0100
Node.js day 3
catalogue
Promise object
Synchronous asynchronous in Promise
Using Promise to resolve callback hell
Promise package
Third party then FS solution callback hell
async and await keywords
async keyword
await keyword
async and await resolve callback hell
4. async and await read JSON file cases
Promise object
An object added in ES6 is ma ...
Posted by welshy123 on Wed, 26 Jan 2022 07:57:23 +0100