javascript - JS garbage collection mechanism

When we assign null to a global variable to actively dereference and release memory, is this a reference counting strategy? Doesn’t it mean that JS’s garbage collection mechanism only uses mark and clear? Does the mark clearing strategy not involve dereferencing?

扔个三星炸死你 2017-07-05 11:02:09 0  2  1085

My multiply (*) command doesn't calculate

My asterisk is not working, when I do the calc() function and do the multiplication notation (i.e. the asterisk), the function is not working. I want to solve this problem as soon as possible because I am learning programming and I need your help in solving it - - mark size: calculation (var(--cell-...

P粉883223328 2024-04-04 21:18:17 0  1  447

What is the difference between HTML tags <a></a> and <a href=""></a>?

Some websites use [url]website address[/url] in their text area and cannot add anchor text there, can someone explain this to me? I'm confused about this [url][/url]. I know how html anchor tag works but not the second one. Thanks I tried googling and couldn't find any solution, hope someone can exp...

P粉512363233 2024-04-02 22:46:16 0  2  592

Using Jinja template/Flask to implement nested HTML paragraph rendering with bold modification

I'm looking to create a function that removes words from a sentence and then replaces the removed word with other words obtained from a dictionary API search. Very simply, this is a function that checks if a word in a sentence belongs to a list of removed words, if so, replaces it with a replacement...

P粉170438285 2024-03-22 13:59:22 0  1  712

Access error

Parse error: syntax error, unexpected 'class' (T_CLASS), expecting identifier (T_STRING) or variable (T_VARIABLE) or '{' or '$' in C:\PHPStudy\WWW\tp5\thinkphp\base.php&nb

hello sun 2018-05-06 15:19:28 0  0  1100

Add line breaks after two conditions are met: no more than "x" characters and ending with a comma or period

I'm working on a small project. The goal of this project is to strip the formatting (double spaces, numbers, and newlines) and then output the value with a line wrap every "x" characters, but make sure it ends with a comma or period. For example...if I set the character limit to 50 (after ...

P粉478835592 2024-04-03 09:17:09 0  1  459

Regular expression to replace several symbols with HTML tags

I'm trying to build a regular expression that replaces all symbols "$$" with some HTML tags, such as <someTag></someTag>. I use this regex, but it doesn't cover all cases: \$\$(\S[^\*]+\S)\$\$'aaa$$123$$c$ddd'.replace(/\ $\$(\S[^\*]+\S)\$\$/g,'<a1>$1</a1>')//works'a...

P粉362071992 2024-04-01 21:01:01 0  2  544

How can I make text turn into a new element (like a divider) when clicked?

I'm trying to find a way to make certain text on the page turn into separators/new elements when clicked. I don't know how to explain it, but like, imagine an image with a title below it - click the title, and then the image above becomes like a text box/different images/scrollable separator. I'm tr...

P粉872101673 2024-04-04 11:21:03 0  1  3807

Center flex items in a container when surrounded by other flex items

I have a flexbox (see code snippet below as an example). I want to set it up so that in all cases, in the center of the flex-box, the other spans will flow around it, based on their markers. I'm basically looking for align-selfCSS code, but for the main axis, not the horizontal axis (which might hel...

P粉042455250 2023-08-25 14:40:25 0  2  529

Sage Pay/Opayo Forms Integration - PHP 8.1 - PHP Fatal Error: Uncaught Error: Attempt to assign property 'start' on null

I'm glad there are similar questions but I can't get any solution to work with my (inherited) code so any help you can provide would be greatly appreciated. We use SagePay/Opayo payment gateway via form integration. Upon completion/failure, the customer will be redirected to a URL on our website wit...

P粉872182023 2023-09-07 22:16:21 0  1  585

Prevent click events with touch actions

I have a div that contains touch-action:pan-y; The div has an anchor tag around it. Now if you click on the div, the link will work and you will be redirected. However, if I swipe on the div and release the swipe, then click on the div, the link won't work on the first click, but it will work on the...

P粉575055974 2023-09-12 22:06:25 0  1  689

Ways to fix issue 2003 (HY000): Unable to connect to MySQL server 'db_mysql:3306' (111)

I recently tried to containerize my FastAPIPython server (also for replication/doubling purposes). Before, I had just a MySQL server in a Docker container and everything was fine, but when I also made my web server a service, it couldn't connect to the MySQL server, so now the application doesn't wo...

P粉178132828 2023-09-05 11:18:47 0  1  828

Experiment with sorting after query limit

So this is my first question here, please forgive me if something is wrong. I'm trying to make a sort query based on constraints. So there is a Customers table with 90 records. I want to first perform a query limited to 3 records, and then sort the results of this query by a column called ContactNam...

P粉237125700 2023-09-05 14:46:42 0  1  727

CSS Grid: Create new row when child content overflows column width

I have a two column layout based on CSS grid. When the content of the second column exceeds 1fr I want to create a new row. As it currently stands, the content simply overflows the column. One requirement of this layout is that the items in the right menu column are in one row. I achieve this with: ...

P粉212114661 2023-09-05 15:18:28 0  1  618

PHP full text search functionality using AND, OR and NOT operators

Newbie question: I'm trying to implement a full text search on a search string using php and eloquent. $searchstring="+(victimsuspect)+crime-covid";$searchresult=RssItem::whereRaw("MATCH(description)AGAINST('$searchstring'INBOOLEANMODE)")->ge

P粉076987386 2023-09-05 15:06:32 0  1  580

Shortest way to convert all PHP types to string

I'm writing a general system that I hope can one day be applied to fields like medicine (i.e. it's "scientific"). I think the best way is to represent all the data in php with strings (true will be "true", false will be "false" and so on). The reason for this is that in...

P粉369196603 2023-09-05 15:34:44 0  1  1008

How to get average of DATETIME column in MySQL while grouping by other columns

I'm creating and populating a MySQL table using the following query: SETtime_zone='+00:00';CREATETABLEtimestamp_n_datetime(idINT,timeDATETIME,avg_timeDATETIME);INSERTINTOtimestamp_n_datetime(id,time,avg_time)VALUES("1","2023-01-0310:

P粉460377540 2023-09-05 11:46:21 0  1  507

Multi-device (mobile phone) synchronization - React Native

I'm trying to create a Lightshow that will launch on all users' mobile devices at the same time (can have up to 2000-3000 users). All users will use the Internet (Wi-Fi or mobile data). In our FE we use Apollo for subscriptions and it works like a charm. But the problem is, user A can get subscribed...

P粉151466081 2023-09-05 11:58:38 0  1  699