<div class="box" style="background: red;">box</div>

 <div class="box" style="background: blue;">box</div>

 <div class="box" style="background: yellow;">box</div>

 <div class="box" style="background: red;">box</div>

 <div class="box" style="background: blue;">box</div>



 <script>

function inter(i){

var οnclick=function(e){

console.log(i);

}

return onclick;

}

var box = document.querySelectorAll('.box');

for(var i=0;i<box.length;i++){

box[i].οnclick=inter(i);

}


 </script>