All Questions

2
answers

What do "n", numbers and signals mean in the "nth-child" or "nth-last-child" selectors?

I have always used the n combined with the nth-child or nth-last-child selector in CSS, but I still can not fully understand its meaning. For example: p:nth-child(3n+0) { background: red; } <p>Teste</p>...
asked on 23.08.2016 / 16:04
2
answers

FieldError: Relation fields do not support nested lookups

I'm trying to do a query in Django with several joins , and I came across this error that I do not know what it means: Tag.objects.filter(dset__descendant__entities__entity=e)    FieldError: Relation fields do not support nested lookups...
asked on 22.01.2016 / 19:10
2
answers

Is there any API to send message through WhatsApp using PHP?

Is there an API for sending a message to a person's WhatsApp using PHP?     
asked on 20.02.2015 / 14:09
4
answers

Is "private" in classes in C # optional?

What is the difference between private string abc = ""; and string abc = ""; ? Is there a difference or is it just the writing that changes? I did a test with and without the private and saw no difference, it worked equally. E...
asked on 12.09.2017 / 22:24
2
answers

Get "waves" of frequency of sound or music

How do I display the sound waves of any sound (music)? I do not know if it's possible to get this with JS or some other language. Waves of this type: Anexampleis how SoundCloud does , displaying a kind of wave of the audio being played. I...
asked on 10.04.2015 / 19:28
3
answers

What are Proxy, Gateway and Tunnel in HTTP protocol?

In the specification of the HTTP protocol, more precisely in the RFC 7230 , the possibility of intermediate entities between the < in entity (AU), the entity that performs the HTTP request, and the origin server (O) entity that will respond...
asked on 09.08.2017 / 23:46
2
answers

What is the LOCK TABLES command for?

These days I came across a snippet of a SQL that had the command LOCK TABLES . I had never seen this before, and from what little I could see, it seems to me that this would be to lock the table during insertion or update. But I want...
asked on 17.08.2018 / 18:19
3
answers

How to determine the approximate location of the user by IP?

When I use search engines for certain searches, mostly related to maps or commercial establishments, these systems often serve me relevant results for my geographical location. When I'm on the PC, search engines may not even know my geographi...
asked on 05.10.2014 / 22:23
4
answers

In git, how do I edit the description of a committed commit?

In case you need to change the description of a commit , to make the description clearer, or specify which issue it is linked. I would like to know how to edit the message that comes with commit after it has been executed.     
asked on 17.12.2013 / 21:06
3
answers

Difference between% i and% d

Is there any difference between printf("%d", x); and printf("%i", x); ? I know the two return the same result, does it have some sort of convention adopted to always use %d ?     
asked on 12.09.2016 / 20:41