jQuery get Data Attribute
HTML
<button data-id="btn-1" value="Hello">Hello World!</button>
JavaScript
console.log($("button").attr("data-id"));
console.log($("button").data("id"));
<button data-id="btn-1" value="Hello">Hello World!</button>
console.log($("button").attr("data-id"));
console.log($("button").data("id"));