• Skip to main content
  • Skip to primary sidebar

RNTLab.com

The Ultimate Shortcut to Learn Electronics and Programming with Open Source Hardware and Software

  • Courses
  • Forum
    • Forum
    • Ask Question
  • Shop
  • Account
  • Blog
  • Login

URL Parameter "+" signs why?

Q&A Forum › Category: ESP32 › URL Parameter "+" signs why?
0 Vote Up Vote Down
David asked 12 months ago

In the Servers Book project 2.2 – Web Server – Control MultipleOutputs (Toggle Switches)
This line is used to send the update request when a slider is activated
xhr.open(“GET”, “/update?output=”+element.id+”&state=1”, true);
Why are the “+” signs requied to top and tail element.id?

3 Answers
0 Vote Up Vote Down
Sara Santos Staff answered 12 months ago

Hi.

The plus signs are concatenating the request with the string that will be returned by “element.id”.

So, imagine the element.id returns “2”, the request would be on the following URL:

/update?output=2&state=1

I hope this is clear.

Regards,
Sara

0 Vote Up Vote Down
David answered 12 months ago

Thanks for that Sara, I hadn’t realised that the XMLHttpRequest() parameter was one continuous string, but I should have done – guilty of overthinking it!

0 Vote Up Vote Down
Sara Santos Staff answered 12 months ago

Hi.
No problem.
I’ll mark this issue as resolved. If you need further help, you just need to open a new question in our forum.
Regards,
Sara

Primary Sidebar

Login to Ask or Answer Questions

This Forum is private and it’s only available for members enrolled in our Courses.

Login »

Latest Course Updates

  • [eBook Updated] Firebase Web App with ESP32 and ESP8266 (version 1.2) April 25, 2022
  • [eBook Updated] MicroPython Programming with ESP32 and ESP8266 (version 1.3) February 7, 2022

You must be logged in to view this content.

Contact Support - Refunds - Privacy - Terms - MakerAdvisor.com - Member Login

Copyright © 2013-2022 · RandomNerdTutorials.com · All Rights Reserved