JSFiddle - React, Tailwind, and code Playground

HTML

<input type="hidden" name="item_name" class="course_name" value="Exam1">      
<input type="hidden" name="amount" class="amount" value="1">
<input type="hidden" name="item_name" class="course_name" value="Exam2">      
<input type="hidden" name="amount" class="amount" value="100">
<input type="hidden" name="item_name" class="course_name" value="Exam3">      
<input type="hidden" name="amount" class="amount" value="1000">

JavaScript

$(function(){
	var amount = [];
  var course = [];
	$('.amount').each(function(){ 
  	amount.push($(this).val());
  });
  $('.course_name').each(function(){
    course.push($(this).val());
  });
  console.log(amount.join(',')); //comma seperated value
  console.log(course.join(',')) //comma seperated value
});