Sometimes when developing js inside a module, you will see the following message:

Uncaught ReferenceError: jQuery is not defined(anonymous function).
Uncaught TypeError: $(…).customjs is not a function.

This is due to AMD(asynchronously module dependencies) nature of require js, and you can fix it in two different ways:

• Use a requirejs-config.js file in your web directory, with the following pattern:
  
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  var config = {     paths: {             'my_js_name': 'Vendor_Module/js/my_js_name.min'     },     shim: {             'my_js_name': {                 deps: ['jquery'] //gives your parent dependencies name here             }     } };

• Use requirejs concept (lazy load), so load jquery first then write your jquery code:
  
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  require(['jquery'],function($){       $(document).ready(function(){          alert('ok');       });   });

  
   

After that, remember to re deploy your static content files, and try again.