Javascript get all objects class

HTML DOM Document getElementsByClassName()

Get all elements with both the «example» and «color» classes:

Description

The getElementsByClassName() method returns a collection of elements with a specified class name(s).

The getElementsByClassName() method returns an HTMLCollection.

The getElementsByClassName() property is read-only.

HTMLCollection

An HTMLCollection is an array-like collection (list) of HTML elements.

The elements in a collection can be accessed by index (starts at 0).

The length Property returns the number of elements in the collection.

See Also:

Syntax

Parameters

Return Value

More Examples

Change the background color of all elements with >

const collection = document.getElementsByClassName(«example»);
for (let i = 0; i < collection.length; i++) collection[i].style.backgroundColor = "red";
>

Related Pages

Browser Support

document.getElementsByClassName() is a DOM Level 1 (1998) feature.

It is fully supported in all browsers:

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Get all instances of class in Javascript

but I can’t seem to find one.. How can I run a particular class method on all instances of this class in Javascript? For example: Say when I click on the hr with the id how would I find all instances of class until the next instance of class ?

Get all instances of class in Javascript

I thought there would already be an answer for this but I can’t seem to find one.. How can I run a particular class method on all instances of this class in Javascript?

This has to be done in a situation where I do not know the names of the instances. I think I could use some sort of static variable inside my class to store all instances, but this doesn’t seem to exist in JS

So how to call my method on all existing instances of my class? Note : just for clarification : I’m not speaking about CSS classes, I’m speaking about objects.

Edit : By Class in Javascript, I mean the creation of a new object on a function:

function something() < >var instance = new something(); 

You can create a static array and store it on your constructor function:

MyClass.allInstances = []; MyClass.allInstances.push(this); 

However, you need some way to figure out when to remove instances from this array, or you’ll leak memory.

In Chrome 62+ you can use queryObjects from the console API — which will not work in native JavaScript code but in the console so it’s great for debugging .

class TestClass <>; const x = new TestClass(); const y = new TestClass(); const z = new TestClass(); queryObjects(TestClass) 

You’ll have to provide a custom implementation.

I would do something like this :

function Class() < Class.instances.push(this); >; Class.prototype.destroy = function () < var i = 0; while (Class.instances[i] !== this) < i++; >Class.instances.splice(i, 1); >; Class.instances = []; var c = new Class(); Class.instances.length; // 1 c.destroy(); Class.instances.length; // 0 

function Class() <>; Class.instances = []; Class.create = function () < var inst = new this(); this.instances.push(inst); return inst; >; Class.destroy = function (inst) < var i = 0; while (Class.instances[i] !== inst) < i++; >Class.instances.splice(i, 1); >; var c = Class.create(); Class.instances.length; // 1 Class.destroy(c); Class.instances.length; // 0 

Then you could loop through all instances like so :

Class.each = function (fn) < var i = 0, l = this.instances.length; for (; i < l; i++) < if (fn(this.instances[i], i) === false) < break; >> >; Class.each(function (instance, i) < // do something with this instance // return false to break the loop >); 

Sorry for such a late reply, but I found myself trying to achieve this and I think this may be a simpler answer.

Say you want all instances of class MyClass, only get instances created at top window level (not including instances created inside a closure):

Html — Get list of all input objects using JavaScript, For instance, if we have a div element in our element variable, we can find all of the span s with the class foo that are inside that div like this: var fooSpans = element.querySelectorAll («span.foo»);

Using jQuery, how do I find all instances of a class that appear between another class

Say when I click on the hr with the id click how would I find all instances of class indent until the next instance of class highlight ?

That’s seems to select all .indents regardless of .highlights. Try this:

$('tr.highlight').click(function() < var row = $(this).next(); var selection = false; while(row.hasClass('indent')) < if(!selection) < selection = row; >else < selection.add(row); >row = row.next(); > >); 

This applies the click only to the highlight with «click» and returns only the indents between «click» and the next highlight it encounters.

It uses the jQuery ~ «next siblings» selector to do a little more of the work for you.

$("#click").bind('click', function() < var good = true; $("#click ~ tr").each(function(e) < if (this.className == "highlight") < good = false; >if (good && this.className == "indent") < this.style.background="red"; >>); >); 

JavaScript Classes, A JavaScript class is not an object. It is a template for JavaScript objects. Using a Class. When you have a class, you can use the class to create objects: Example. let myCar1 = new Car(«Ford», 2014); let myCar2 = new Car(«Audi», 2019); Try it Yourself » The example above uses the Car class to create two Car objects. The …

$.toggle() all instances of a class

Hello i am trying to toggle hide show comments, I originally had it working just fine, because i thew all my comments inside of a single div with class .forum-comments .

However, now I am breaking up each comment with divs that have .forum-comments class

This is the original code:

 // Button dynamic comment show $("#forum").delegate(".btn-forum-comment-show", "click", function() show'; var hide = ' hide'; if(change == ' show') < $(this).parent().find(".btn-forum-comment-show").html(hide); >if(change == ' hide') < $(this).parent().find(".btn-forum-comment-show").html(show); >>); 

the function $(this).parent().next(«.forum-comments»).toggle(); stopped working as i have each comment with the .forum-comments class. So it only toggles the first comment on and off. the rest remain unaffected. How can i change this behavior so that each comment is toggled.?

these comments by default are hidden with style=»display:none» and with $.toggle() are enabled/disabled

here is a dump of the entire section:

Discussion
 
This is the student forum, where any student can post information with the option to add tags!

$(this).parent().next(".forum-comments").toggle(); 

var $parent = $(this).parent(); $parent.next(".forum-comments").length ? $parent.next(".forum-comments").toggle() : $parent.prev(".forum-comments").toggle() 

$(this).parent().nextAll(".forum-comments").toggle(); 

class Student < constructor(name, birthDate) < this.name = name; this.birthDate = birthDate; >get age() < return 2018 - this.birthDate; >display() < console.log(`name $, birth date: $`); > >console.log(Object.getOwnPropertyNames.call(Student));

Object.getOwnPropertyNames.call(Student) 

class Student < constructor(name, birthDate) < this.name = name; this.birthDate = birthDate; >get age() < return 2018 - this.birthDate; >display() < console.log(`name $, birth date: $`); > >console.log(Object.getOwnPropertyNames(new Student));

getElementsByClassName(names) 

.getElementsByClassName("test"); 

.getElementsByClassName("red test"); 

.getElementById("main").getElementsByClassName("test"); 

.getElementsByClassName("test")[0]; 

const testElements = document.getElementsByClassName("test"); const testDivs = Array.prototype.filter.call( testElements, (testElement) => testElement.nodeName === "DIV", ); 

html lang="en"> body> div id="parent-id"> p>hello world 1p> p class="test">hello world 2p> p>hello world 3p> p>hello world 4p> div> script> const parentDOM = document.getElementById("parent-id"); const test = parentDOM.getElementsByClassName("test"); // a list of matching elements, *not* the element itself console.log(test); // HTMLCollection[1] const testTarget = parentDOM.getElementsByClassName("test")[0]; // the first element, as we wanted console.log(testTarget); // 
hello world 2 script> body> html> 

span class="orange fruit">Orange Fruitspan> span class="orange juice">Orange Juicespan> span class="apple juice">Apple Juicespan> span class="foo bar">Something Randomspan> textarea id="resultArea" style="width:98%;height:7em">textarea> 

// getElementsByClassName only selects elements that have both given classes const allOrangeJuiceByClass = document.getElementsByClassName("orange juice"); let result = "document.getElementsByClassName('orange juice')"; for (let i = 0; i  allOrangeJuiceByClass.length; i++)  result += `\n $allOrangeJuiceByClass[i].textContent>`; > // querySelector only selects full complete matches const allOrangeJuiceQuery = document.querySelectorAll(".orange.juice"); result += "\n\ndocument.querySelectorAll('.orange.juice')"; for (let i = 0; i  allOrangeJuiceQuery.length; i++)  result += `\n $allOrangeJuiceQuery[i].textContent>`; > document.getElementById("resultArea").value = result;