JSFiddle - React, Tailwind, and code Playground

HTML

<form>
<textarea>
one
two 
three
</textarea>
<input type="submit" value="clicky">
</form>

CSS

textarea {
 width: 300px;
 height: 200px;        
}

JavaScript

$('form').submit(function(e){
   e.preventDefault();
   e.stopPropagation();
    
   var o = {};
   $( $('textarea').val().split(/\n|\r/) ).each(function(i){
      o[i] = this;
    });   
    var jsonString = JSON.stringify(o);   
    console.log(jsonString);
});