What's the difference between $get and $find in JavaScript?

问题

I'm a .NET programmer who've just started to learn more about client side scripting, and I was wondering sometimes you use $get('value') and $find('value') and I've discovered that these are just shortcuts for document.getElementById('value') and Sys.Application.findComponent('value'), respectively.

However, I still don't understand: what is the difference between these two functions in JavaScript? What exactly are they looking up/retrieving when invoked?

Thanks in advance.

回答1:

$get & $find are shortcut functions Microsoft has built into their Ajax JavaScript Library.

$get is short for the standard JavaScript GetElementById function. $find is short for .Net's findComponent() function. This is not a standard JavaScript function and is specific to Microsoft's Ajax JavaScript library.

Matt Berseth does a great write up of the differences & usages here.

回答2:

1. $get(elementId) returns a DOM element, same as document.getElementById(elementId)

2. $find(elementId) returns an ASP.NET-AJAX JavaScript object, with it's own functions and properties.

   Inconveniently, in Microsoft Ajax those objects are always attached to some DOM element as it's attribute and are related to that DOM element in some ways, so that's why you have to pass element ID to retrieve the object data.

回答3:

$get is the shortcut function built by Microsoft into their ASP.net Ajax javascript library. It is short for getElementById method of javascript. It is not standard and is specific only to Microsoft.

It accepts two parameters :

• ID: id of the element. Required Field
• Element: Parent element to start the search. Optional Field

来源：https://stackoverflow.com/questions/2726304/whats-the-difference-between-get-and-find-in-javascript