无法在HtmlCollection上进行迭代

Question

I have an issue with a simple code

    var x = document.getElementsByTagName("th");
    var plop = Array.prototype.slice(x);
    console.log(x);
    console.log(x.length);
    console.log(plop);

output

[item: function, namedItem: function]
0: th.fc-day-header.fc-sun.fc-widget-header.fc-first
1: th.fc-day-header.fc-mon.fc-widget-header
2: th.fc-day-header.fc-tue.fc-widget-header
3: th.fc-day-header.fc-wed.fc-widget-header
4: th.fc-day-header.fc-thu.fc-widget-header
5: th.fc-day-header.fc-fri.fc-widget-header
6: th.fc-day-header.fc-sat.fc-widget-header.fc-last
length: 7__proto__: HTMLCollection
    controller.js:309 0
    controller.js:310 []

Why does I see lenght 7 here and the x.length gives 0 ?

Thanks in advance

update : I set the code in

$scope.$on('$viewContentLoaded', function(){
}

And it works now. I'm not yet able to set an onclick method but it progress ^^

Answer 1

$scope.$on('$viewContentLoaded', function(){

var x = document.getElementsByTagName("th");
var arr =  Array.prototype.slice.call(x);
        console.log(arr);
        for (var i = 0; i < arr.length; i++) {
           // console.log("iterate");
            console.log(arr[i]);
            arr[i].onclick = function(){
                console.log("lol");
            };
        }
};

Answer 2

You are missing the .call() when you're trying to make an array copy from the HTMLCollection . Instead of this:

var x = document.getElementsByTagName("th");
var plop = Array.prototype.slice(x);

You can do this:

var x = document.getElementsByTagName("th");
var plop = Array.prototype.slice.call(x);
console.log(plop);

---

Note: you don't need to make an array copy just to iterate over it. You can iterate an HTMLCollection directly:

var items = document.getElementsByTagName("th");
for (var i = 0; i < items.length; i++) {
    console.log(items[i]);
}