Is there an "exists" function for jQuery?

Taking a Deeper Dive

When presence isn't enough: advance checks

Sure, knowing an element exists is cool. But what about its absence or specific conditions? Let's spice things up!

Ghost elements: absentees' roll call

if (!$('selector').length) {
  // Ghost alert! Element is MIA (Missing In Action)
}
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Invert the condition with !. Now we're looking for elusive elements. Amazing for treating scenarios where something important is shockingly missing.

The .is() whispers: did you say custom criteria?

if ($('selector').is('*')) {
  // Right there! The element has been spotted!
}
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.is() can be super helpful for a more specific search criteria. You know, like checking for attributes or classes.

Direct hit: index-based existence probe

if ($(selector)[0]) {
  // Bullseye! Direct hit confirms existence.
}
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Directly indexing the jQuery object gives you a shortcut to the DOM element. It's like jumping the queue at a concert!

Efficient code: or how to be a jQuery Ninja!

Say no to .exists() sugar coating:

// This might make you popular, but it's wrong in so many levels...
jQuery.fn.exists = function(){return this.length>0;}
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Creating an .exists() method might make your code look sleek. But remember, with great power comes great responsibility. And this could lead to:

• Raising eyebrows: More utterance, more function calls.
• Library turf wars: What if another library has a warrior called exists?
• Breaking the jQuery chain-gang: jQuery prides itself on chainability. Let's not cause a gang war here.

Better stick with native checks to keep the code precise, efficient and conflicts at bay.

JavaScript vs. jQuery: The Fast and the Furious

Unleashing the beast: Native over jQuery

When speed is the need and you're looking at IDs, JavaScript doesn't disappoint.

if (document.getElementById('element_id')) {
  // The JavaScript beast caught the element. RAWR!
}
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Native document methods can outpace jQuery, when you suddenly find yourself caught up in a Fast and Furious kind of situation.

Different strokes for different folks

Dynamic scenarios: Ajax and the vanishing elements

ajaxCall().done(function() {
  if ($('#newElement').length) {
    // New element in-play. Let's roll the dice!
  }
});
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Remember those pesky dynamic pages, where elements are created and destroyed faster than popcorns at a movie theater? Consistent check for element existence can potentially save the day.

Plugin checks: Because not every house is suitable for a party!

if ($('.datepicker').length) {
  $('.datepicker').datepicker(); // Party Time. Oh wait, only if house exists!
}


We wouldn't want to host a party at a nonexistent venue, right? Check if the venue (element) exists before setting up the party (plugin initialization).