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I wouldn't think its possible at all, but I'm just wondering because my friend has this on his page:

<html>
    <head></head>
    <body>
        <script>
            $(function(){
              // ...
            });
        </script>
        <div><span>html stuff</span></div>
        <script src="jquery-1.7.js"></script>
    </body>
</html>

So I was just wondering, is that valid? Will jQuery take that $(function(){}); block and make it work after its done loading?

I wouldn't think its possible at all, but I'm just wondering because my friend has this on his page:

<html>
    <head></head>
    <body>
        <script>
            $(function(){
              // ...
            });
        </script>
        <div><span>html stuff</span></div>
        <script src="jquery-1.7.js"></script>
    </body>
</html>

So I was just wondering, is that valid? Will jQuery take that $(function(){}); block and make it work after its done loading?

  • javascript
  • jquery
Share Improve this question asked Nov 19, 2011 at 17:07 trusktrtrusktr 45.6k58 gold badges210 silver badges287 bronze badges 3
  • 7 Well, does it? It is on a live page, you say... – GolezTrol Commented Nov 19, 2011 at 17:09
  • Yeah, after testing, it didn't work. I guess I really wanted to see if I could get an answer faster here or by testing... Yeah i know that's shady! But I was able to test faster. I'll avoid such questions in the future. – trusktr Commented Nov 19, 2011 at 17:56
  • This issue happens often enough it's handy to have a question like this to point people at. – T.J. Crowder Commented Apr 8, 2017 at 12:39
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1 Answer 1

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No it doesn't work like your friend expects it to because $ will be undefined at that point so calling the function $ with the argument function(){ } will cause a javascript error stating that $ is undefined. You must load jQuery before trying to use it.

Your friend might be confused into thinking that $ is special, but $ is a name like any other. I.e:

function jQuery(){
 // do stuff
}

and 

function $(){
  // do stuff
}

would do the exact same thing. Having those definitions in an external file would not make them callable before they were loaded.

Tangental note: It is not strictly impossible to write code that eventually will use jQuery before jQuery has loaded, but you would be putting your code in something that would be called only once jQuery has loaded. I'm not aware of any jQuery convention of doing this, as it's not very mon to do that with this library, but Facebook does it like this: https://developers.facebook./docs/reference/javascript/ I don't think your friend should actually attempt this until he is more familiar with JavaScript.

本文标签： javascriptCan you write jQuery code inline before loading jQueryStack Overflow

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