CODEWITHSUNDEEP
javascriptjquery
Daddy Warbox
Daddy Warbox

Reputation: 4598

Assorted jQuery questions

1.) What's the difference between these two queries, exactly?

$( "#orderedlist li" )
$( "#orderedlist>li" )

2.) In the jQuery file itself there is a function that returns the following:

function now(){
    return +new Date;
}

What does that mean? I've never seen +new before.

3.) In a brief skimming of a tutorial, I observed the following samples:

// use this to reset a single form
$( "#reset" ).click( function()
{
    $( "form" )[0].reset();
});

// use this to reset several forms at once
$( "#reset" ).click( function()
{
    $( "form" ).each( function()
    {
        this.reset();
    });
});

When I try to reference my own queries by array indexes, they don't seem to work. Yet this example clearly did when I tested it. What could I be doing wrong?

Edit: I'll put this one into its own question soon. Edit 2: Actually I may be able to debug it myself. Hang on...

I have guesses to each of these, but short of dissecting the jQuery file itself in full, I'm not completely certain what's at work here. Help appreciated.

Upvotes: 4

Views: 259

Answers (1)

RichieHindle
RichieHindle

Reputation: 281555

Question #1:

  • #orderedlist li is a "descendant selector": an li anywhere within an #orderedlist.
  • #orderedlist>li is a "child selector": an li which is a direct child of an #orderedlist.

Question #2:

That's using the unary plus operator - it's equivalent to:

return Number(new Date);

see: http://xkr.us/articles/javascript/unary-add/ - it gives the number of milliseconds since the UNIX epoch.

Question #3:

I don't know about this one. Could you post a minimal failing example?

Upvotes: 8

Related Questions