Why forEach does not exist on NodeListOf

Question

My code:

    var checkboxes = this.element.querySelectorAll(\"input[type=checkbox]\") as NodeListOf;
    checkboxes.forEach(ele =>         


        

Answer 1

There is no guarantee forEach will exist on this type - it can, but not necessarily (e.g. in PhantomJS and IE), so TypeScript disallows it by default. In order to iterate over it you can use:

1) Array.from():

Array.from(checkboxes).forEach((el) => { /* do something */});

2) for-in:

for (let i in checkboxes) {
  if (checkboxes.hasOwnProperty(i)) {
    console.log(checkboxes[i]);
  }
}