jQuery reference error - Stack Overflow

Question

I want to import the jquery package, but the browser reports an error. What is the reason?
**Uncaught ReferenceError: $ is not defined

at a.js:1

(anonymous) @ a.js:1**

Answer 1

a.js depends on jquery. You need to introduce jquery first and then a.js. Take a look at the page to see if it is in this order.
Additional explanation I tried it on chrome and it worked.

Answer 2

$ is not defined, which means it has not been introduced successfully. Pay attention to the js reference order, jQuery should be placed first