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Search DOM for elements based on part of the class name [duplicate]

If I have the following:
<div class="apple-monkey"></div>
<div class="apple-horse"></div>
<div class="cow-apple-brick"></div>
I can use the following selector to find the first two DIVs:
$("div[class^='apple-']")
However, if I have this:
<div class="some-other-class apple-monkey"></div>
<div class="apple-horse"></div>
<div class="cow-apple-brick"></div>
It will only find the second DIV, since the first div's class is returned as a string (I think) and doesn't actually start with 'apple-' but rather 'some-'
One way around that is to not use starts with, but instead contains:
$("div[class*='apple-']")
The problem with that is it will also select the 3rd DIV in my example.
Question: Via jQuery, what is the proper way to use predicate selectors on individual class names, rather than the entire class attribute as a string? Is it just a matter of grabbing the CLASS, then splitting it into an array and then looping through each individual one with regex? Or is there a more elegant/less verbose solution?

Classes that start with "apple-" plus classes that contain " apple-"
$("div[class^='apple-'],div[class*=' apple-']")

I'd recommend making "apple" its own class. You should avoid the starts-with/ends-with if you can because being able to select using div.apple would be a lot faster. That's the more elegant solution. Don't be afraid to split things out into separate classes if it makes the task simpler/faster.

While the top answer here is a workaround for the asker's particular case, if you're looking for a solution to actually using 'starts with' on individual class names:
You can use this custom jQuery selector, which I call :acp() for "A Class Prefix." Code is at the bottom of this post.
var test = $('div:acp("starting_text")');
This will select any and all <div> elements that have at least one class name beginning with the given string ("starting_text" in this example), regardless of whether that class is at the beginning or elsewhere in the class attribute strings.
<div id="1" class="apple orange lemon" />
<div id="2" class="orange applelemon banana" />
<div id="3" class="orange lemon apple" />
<div id="4" class="lemon orangeapple" />
<div id="5" class="lemon orange" />
var startsWithapp = $('div:acp("app")');
This will return elements 1, 2, and 3, but not 4 or 5.
Here's the declaration for the :acp custom selector, which you can put anywhere:
$(function(){
$.expr[":"].acp = function(elem, index, m){
var regString = '\\b' + m[3];
var reg = new RegExp(regString, "g");
return elem.className.match(reg);
}
});
I made this because I do a lot of GreaseMonkey hacking of websites on which I have no backend control, so I often need to find elements with class names that have dynamic suffixes. It's been very useful.

this is for prefix with
$("div[class^='apple-']")
this is for starts with so you dont need to have the '-' char in there
$("div[class|='apple']")
you can find a bunch of other cool variations of the jQuery selector here
https://api.jquery.com/category/selectors/

<div class="apple-monkey"></div>
<div class="apple-horse"></div>
<div class="cow-apple-brick"></div>
in this case as question Josh Stodola answer is correct
Classes that start with "apple-" plus classes that contain " apple-"
$("div[class^='apple-'],div[class*=' apple-']")
but if element have multiple classes like this
<div class="some-class apple-monkey"></div>
<div class="some-class apple-horse"></div>
<div class="some-class cow-apple-brick"></div>
then Josh Stodola's solution will do not work
for this have to do some thing like this
$('.some-parent-class div').filter(function () {
return this.className.match(/\bapple-/);// this is for start with
//return this.className.match(/apple-/g);// this is for contain selector
}).css("color","red");
may be it helps some one else thanks

Try this:
$("div[class]").filter(function() {
var classNames = this.className.split(/\s+/);
for (var i=0; i<classNames.length; ++i) {
if (classNames[i].substr(0, 6) === "apple-") {
return true;
}
}
return false;
})

Javascript: How to print input to <div> selected by class?

Edit: Thanks for the helpful answers so far! I'm still struggling to print the input to the "right" div, though. What am I missing?
Next to the input field, there is an option to select either "left" or "right". Depending on the selection, the input is to be printed eiether left or right on the click of a button. This is what I have - but it only prints to the left, no matter the selection.
jQuery(document).ready(function(){
$('.button').click(function(){
$('.input').val();
if ($('select').val() == "left"){
$('div.left').html($('.input').val());
}
else {
$('div.right').html($('.input').val());
}
});
});
</script>
Sorry if this is very basic - I am completely new to JS and jQuery.
I'm trying to print input from a form into a div. This is part of the source HTML modify (it's for a university class):
<input type="text" class="input">
<div class="left">
</div>
<div class="right">
</div>
Basically, text is entered into the field, and I need to print this text either to the "left" or the "right" div when a button is clicked.
So far, I have only ever dealt with divs that had IDs, so I used
document.getElementById("divId").innerHTML = ($('.input').val());
But what do I do now when I don't have an ID? Unfortunately, changes to the HTML source are not an option.
Thanks in advance!

Just use normal selectors, like css and jQuery does.
https://api.jquery.com/category/selectors/
in your case:
$('div.left').html($('.input').val());

As you see there are many ways to do this. You can get elements by tag name, class, id...
But the most powerful way is to get it with querySelector
function save() {
var input = document.querySelector('input').value;
document.querySelector('div.left').innerHTML = input;
}
<input type="text" class="input">
<button onclick="save()">Save</button>
<div class="left"></div>
<div class="right"></div>

There are plenty of other ways to target HTML elements, but the one you're looking for in this case is getElementsByTagName(). Note that this returns a NodeList collection of elements, so you'll additionally need to specify the index that you wish to target (starting at 0). For example, if you want to target the second <div> element, you can use document.getElementsByTagName("div")[1].
This can be seen in the following example:
let input = document.getElementsByTagName("input")[0];
let button = document.getElementsByTagName("button")[0];
let div2 = document.getElementsByTagName("div")[1];
button.addEventListener("click", function(){
div2.innerHTML = input.value;
});
<input type="text">
<button>Output</button>
<br /><br />
<div>Output:</div>
<div></div>

Since you have unique class names for each element, document.getElementsByClassName can be used. This will return an array of elements containing the class. Since you only have one element with each class name, the first element of the returned array will be your target.
<input type="text" class="input">
<button onclick="save()">Save</button>
<div class="left"></div>
<div class="right"></div>
<script>
function save() {
var input = document.getElementsByClassName('input')[0].value;
document.getElementsByClassName('left')[0].innerHTML = input;
}
</script>

This is one of the many ways to do what you want:-
Write the following in console:
document.getElementsByTagName("div");
now you can see the total number of div elements used in your current document/page.
You can select one of your choice to work on by using "index number"(as in array index) for that particular div.
Lets say your div having class name = "right" is the 3rd one among the other div elements in your document.
This will be used to access that div element.
document.getElementsByTagName("right")[2].innerHTML = "whatever you want to write";

Understanding the usage of get() in my sorting script

I recently found a code snippet that I would really like to understand:
var buttons = $('#fruit,#vegetable,#meat').click(function() {
$(this).toggleClass('active');
var classes = buttons.filter('.active').map(function() {
return this.id;
}).get().join(',.');
$('div.fruit,div.vegetable,div.meat').hide().
filter('.' + (classes || 'none')).show();
});
The HTML code :
<div style="float:right; padding:25px;">
<button id="fruit" class="active"><span>fruit</span></button>
<button id="vegetable" class="active">vegetable</button>
<button id="meat" class="active">meat</button>
</div>
<div>
<p>Trying to use buttons as an "or" case rather than "and." When choosing fuit or vegetable, I want to see tomato as part of each list, <em>not just</em> when both are selected.</p>
<div class="fruit">
<p>apple</p>
</div>
<div class="vegetable">
<p>pumpkin</p>
</div>
<div class="vegetable">
<p>okra</p>
</div>
<div class="fruit">
<p>orange</p>
</div>
<div class="meat">
<p>beef</p>
</div>
<div class="fruit vegetable">
<p>tomato</p>
</div>
</div>
The fiddle is here.
I do understand how all the methods work in jQuery like toggleclass, filter and map, I also understand how join works in JS, but in this particular example, I am not able to figure out how get() is working or rather what is it's usage in the script is.
I went through the jQuery documentation for get() and I came across this method for the first time; to me, it seems it's very much similar to eq() in jQuery, but I am still not able to figure out why exactly get is being used in my example.
Can somebody explain this to me ?

.get is used here, because .map returns a jquery style object which contains some functions and information about the contained data. But in this scenario only the values stored within the object (the class names of the active buttons) are wanted. .get is used to get an array containing the raw values and with .join(",.") the values from the array get concatenated to a string. This string then get's used to show all div's that should be active according to the selected buttons.

How to remove all elements in a div after a certain div

So I have a div that is drawing in dynamic elements at its bottom and I want to hide these elements, no matter what their IDs are using javaScript/jQuery. Basically my HTML looks like this:
<div class="right-panel">
<div class="info">Text</div>
<form id="the-form">
<input type="hidden" name="first-name" value="">
<input type="hidden" name="last-name" value="">
<input type="hidden" name="state" value="">
</form>
<script>javaScript</script>
<div id="dynamic-id-1">Advertisement 1</div>
<div id="dynamic-id-2">Advertisement 2</div>
</div>
I'd like to ensure that the "dynamic-id-1" and "dynamic-id-2" divs are always removed or hidden no matter what their ID's are (their IDs are subject to change). How do I target these elements without targeting their IDs?
Edit--I tried this, but my approach seems limited, and I couldn't get it to work with multiple divs, even when chaining:
$('#the-form').next().hide();
(Note: unfortunately they don't have a class, there are multiple divs, and the IDs are always completely different. I was hoping there might be novel way to target the last two divs of the wrapping div and hide them)

If the script tag is always before the div's that need removing you could do this -
$('.right-panel > script').nextAll('div').remove();
http://jsfiddle.net/w6d8K/1/
Based on what you tried you could do this -
$('#the-form').nextAll('div').hide();
http://jsfiddle.net/w6d8K/2/
Here are the docs for nextAll() - https://api.jquery.com/nextAll/

The simplest route would be to add classes to the dynamic elements. Something like:
<div class="removable-element" id="dynamic-id-1">Advertisement 1</div>
Then, you can do something like:
$(".right-panel .removable-element").remove()

If only one div at a time is generated dynamically. Add this to dynamic generation:
$('#the-form + div').hide();
Another method to achieve the same (not preferred) is:
$('#the-form').next('div').remove();

You are saying you don't want to target their "id", but is there some specific part in the id that will remain the same ?
like for instance "dynamic-id-" ?
If this is the case you can target them by using a "like selector". The code below would target all divs whose ID is starting with "dynamic-id"
$('div[id^=dynamic-id]').each(function () {
//do something here
});

Target the class instead of the dynamic ID.
<div class="element-to-remove" id="dynamic-id-1" />
<div class="element-to-remove" id="dynamic-id-2" />
$('.right-panel . element-to-remove').remove();

Target a class whether or not it has a number in the name

I'm struggling a bit with this : let's say I have a class in the body <body class="video page"> and in my page I have a pagination which add a number like this <body class="video-2 page"> at each page. I would like to target the class video whether or not it has a number in order to apply some jquery if the condition is filled.
How do I do that?

You can use this attribute selector to select elements that have a class attribute starting with video-:
[class^="video-"]
But for this to work, you’d have to make sure that the video- class is the first one in the element’s class attribute (see http://jsfiddle.net/Czyep/).
It might be better to have the video class and the pagination class be separate, e.g.:
<body class="video page-2 page">

I would split the classes like class="video two page" so that you can still address both classes separately. Nevertheless you can do something like
$('body[class*=video]')

$("body").not(".video");
Should select all bodies wich end with a number. You could also do:
if($("body").is("[class$='video-'")) {}

have you tried something like this this?
$('.video,.video-'+pageNumber).dosomething()

You can use the attribute starts with selector:
$("body[class^='video']");

Assuming I have understood your question correctly I would suggest that you use concatenation in your selector.
I assume that you are aware that you have specified two classes on your body tag namely video and page or video-2 and page. And I therefore assume that page is significant in your selection and should be included in your selector.
Therefore I would use this syntax whilst not as neat as some syntax it is very clear what is going on. Obviously you would need to incorporate this into what ever logic is driving your page selection.
var suffix = "";
$(".video" + suffix + ".page").dosomething(); // select <body class="video page">
suffix = "-2";
$(".video" + suffix + ".page").dosomething(); // select <body class="video-2 page">
Note that there should be no space between the classes in the selector because they have been declared in the same tag in the html.
Had you specified something like
<body class="video"> // body wrapper
<div class="page"> // page wrapper
</div>
</body>
Then a space would be required as you are then looking to match on div page within body with class video or video-2 as appropriate.
suffix = "-2";
$(".video" + suffix + " .page").dosomething(); // select <body class="video-2"><div class="page">