How to add a property to an element method?

Question

The code looks like document.getElementById.a = 1 . This works except in IE. As the document says

the function is also an object

so it can be added properties, right?

Answer 1

In Javascript you can set or get properties on any value unless :

• it is null or undefined
• it has been frozen or sealed

It is usually bad practice to add properties to native objects/methods because doing so may conflict with other code on the page. I imagine there is a better way to do whatever you are doing.

Answer 2

尝试使用方法setAttribute即

document.getElementById('<IDofElement>').setAttribute('a',1);

Answer 3

You can add 'a' to Function prototype. Then it will be available for all Functions.

Function.prototype.a = 1;
console.log(document.getElementById.a); //logs 1
console.log(document.getElementsByClassName.a); //also logs 1

This is not the best solution, but should work even on IE.