dataset

You can work with these data-* attributes in the DOM via the dataset property. The dataset property returns an array of values, indexed by the custom part of the name.

 
<!DOCTYPE HTML> 
<html> 
    <head> 
        <title>Example</title> 
    </head> 
    <body> 
        <p id="textblock" class="Survey numbers" data-Survey="apple" data-sentiment="like"> 
            This is a test.
        </p> 
        <script> 
            
            var elem = document.getElementById("textblock"); 
            for (var attr in elem.dataset) { 
                document.writeln(attr); 
            } 
            document.writeln("Value of data-Survey attr: " + elem.dataset["Survey"]); 
        </script> 
    </body> 
</html>

Click to view the demo