JSFiddle - React, Tailwind, and code Playground

HTML

<ul id="controls"><li id="d1">d1</li><li id="d2">d2</li><li id="d3">d3</li></ul>

JavaScript

var loopvar;
for (loopvar = 1; loopvar <= 3; loopvar++) {
    $('#controls li[id=d' + loopvar + ']').mousedown((function(loopvar){
        return function(e){
            console.log(e);
           console.log('d' + loopvar);
        }
    })(loopvar));
}