[Solved] Dynamical Calculator Javascript

Question

var keys = document.querySelectorAll(".keys span");

for (var i = 0; i < keys.length; i++) {
    keys[i].onclick = function(){
        alert(this.innerHTML);
    }
}

keys is a NodeList so you cannot attach the onclick on that. You need to attach it to each element in that list by doing the loop. To get the value you can then simple use this.innerHTML.

Fiddle

Accepted Answer

var keys = document.querySelectorAll(".keys span");

for (var i = 0; i < keys.length; i++) {
    keys[i].onclick = function(){
        alert(this.innerHTML);
    }
}

keys is a NodeList so you cannot attach the onclick on that. You need to attach it to each element in that list by doing the loop. To get the value you can then simple use this.innerHTML.

Fiddle