Why is this jQuery click function not working?

You are supposed to add the javascript code in a $(document).ready(function() {}); block. i.e. As jQuery documentation states: “A page can’t be manipulated safely until the document is “ready.” jQuery detects this state of readiness for you. Code included inside $( document ).ready() will only run once the page Document Object Model (DOM) is ready for JavaScript code to execute”

Execute PHP function with onclick

First, understand that you have three languages working together: PHP: It only runs by the server and responds to requests like clicking on a link (GET) or submitting a form (POST). HTML & JavaScript: It only runs in someone’s browser (excluding NodeJS). I’m assuming your file looks something like: Because PHP only responds to requests … Read more

Uncaught ReferenceError: function is not defined with onclick

Never use .onclick(), or similar attributes from a userscript! (It’s also poor practice in a regular web page). The reason is that userscripts operate in a sandbox (“isolated world”), and onclick operates in the target-page scope and cannot see any functions your script creates. Always use addEventListener()Doc (or an equivalent library function, like jQuery .on()). … Read more

Show/hide ‘div’ using JavaScript

How to show or hide an element: In order to show or hide an element, manipulate the element’s style property. In most cases, you probably just want to change the element’s display property: Alternatively, if you would still like the element to occupy space (like if you were to hide a table cell), you could change the element’s visibility property instead: … Read more