chaining getElementById

Question

I\'ve been looking for an answer to this question but I could find none so I thought I\'d try StackOverflow.

In javascript, is this valid:

x = document

Answer 1

You can just use y = x.querySelector('#'+'mySecondId'); instead of y = x.getElementById('mySecondId'); in the sample of the question.

Element.getElementById doesn't exist but you can add it as mentioned in other answers, even if it is not recommended to add a method to Element. In case you want absolutely use this kind of solution, below is a possibility:

Element.prototype.getElementById = function(id) {
return this.querySelector("#"+id);
}

One advantage to use element.querySelector instead of document.getElementById inside Element.prototype.getElementById is that element.querySelector is working even if the element is not already in the DOM, such as after creating it with document.createElement.