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There are several divs on my page with classes my_widget-2, my_widget-8, etc.
What JavaScript or jQuery code can I use to get the number "2" (ie. the number that appends the first matching widget)?
Note: If I were to write this question again, I would change the order of these class names and ask for a way to get "8" in order to avoid giving the impression that I want the smaller number.
$( "[class*='my_widget']" ).each ( function () {
var elClasses = $( this ).attr ( 'class' ).split ( ' ' );
for ( var index in elClasses ) {
if ( elClasses[index].match ( /^my_widget-\d+$/ ) ) {
var classNum = elClasses[index].split ( '-' )[1];
alert ( classNum );
break;
}
}
} );
Use the "attributeContains" selector to get all elements that have a class my_widget-*, and then loop trough all the classes the element has searching for you class. Once you find it, extract the number part.
This should do the trick:
$("[class^='my_widget']").each(function() {
var classParts = $(this).attr('class').split('-');
var number = classParts.pop();
});
Please note that it will only work if there is a singular class, otherwise you'd get something like 8 otherclass as a result.
Basic JS approach:
<div id="x" class="widget-2 lang-日本語">foo</div>
function Element_getClassArgument(el, name) {
var classes= el.className.split(' ');
var prefix= name+'-';
for (var i= classes.length; i-->0;)
if (classes[i].substring(0, prefix.length)==prefix)
return classes[i].substring(prefix.length);
return null;
}
Element_getClassArgument(document.getElementById('x'), 'widget'); // 2
If you wanted to include whitespace characters, or a hyphen in a name, you'd have to introduce an encoding scheme of some sort, for example encodeURIComponent. But often you can get away without that.
Wrapping in something with $ in the name is left as an exercise for the reader. :-)
If you want to get the DIV elements with a class my_widget-2, use this selector:
$("div.my_widget-2")
But if you want to get all DIV elements with a class of the form my_widget-N where N is an arbitrary number, try this:
$("div[class]").each(function() {
var matches = this.className.match(/(?:^|\s+)my_widget-(\d+)(?:\s+|$)/g);
if (matches !== null) {
alert(matches);
}
})
Try
element.attr('class').match(/my_widget-(\d+)/)[1]
It should return the column number as a string so just run parseInt() on it
I'm trying to access the class that was matched by a jQuery selector in a callback function. For example, if I have the following HTML,
<p class="someclass sorted-1 anotherclass">test</p>
I'd like to match this element and get the sorted-1 class name. The value 1 is arbitrary. Something like the following. getMatchedClass() is pseudo code. I thought I could get the value from $(this), but I'm not seeing it.
$('[class*=sorted-]').on('click', function() {
var className = getMatchedClass();
console.log(className); // should output 'sorted-1'
});
Does anyone know if this is possible? I'm having a hard time coming up with search terms. I keep getting results on selected values which isn't what I want.
Thanks
Update
Based on #maheer-ali's answer I came up with the following solution.
$(function() {
function column(className) {
const regex = /sorted-([0-9]+)/;
return className.match(regex)[0].replace(regex, '$1');
}
$('[class*=sorted-]').each(function(i, r) {
// col is the dashed number after sorted
// if parsing `sorted-42`, `col` would equal 42
const col = column($(r).context.className);
// Use the `col` value here.
$(r).doSomething({ column: col });
});
});
You can use a match() and regular expression. And get the first element of result array.
$('[class*=sorted-]').on('click', function() {
var className = this.className.match(/sorted-[0-9]+/)[0];
console.log(className); // should output 'sorted-1'
});
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<p class="someclass sorted-1 anotherclass">test</p>
The other way is to use split() and startsWith(). split() the className by " " and use find() to get element element with startsWith the string "sorted-"
$('[class*=sorted-]').on('click', function() {
var className = this.className.split(' ').find(x => x.startsWith('sorted-'))
console.log(className); // should output 'sorted-1'
});
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<p class="someclass sorted-1 anotherclass">test</p>
The callback function that you're passing is called with the event that triggered it.
You can access event.target.classList to get an array of all of the classes on that object. If you have a fixed set of class patterns you're looking for, you could search that list for the class.
Hope this helped!
How to do the equivalent of this in jquery?
var myCollection = $(".sortable");
var link = _.find(myCollection, function(item){
return someInput.value == $(item).data("sort-column");
});
Knowing why you're trying to do this would help, but I don't think there's a built in function to replace for the underscore one. One of the comments mentions filter, but that is not the same as underscore's _.find, since find returns for the first found element.
That's the only suggestion I have, but that's just a forEach
var item
$.each(myCollection,function( index, element ) {
if ( condition ) {
item = element
return false
}
});
You can use $.grep
Finds the elements of an array which satisfy a filter function. The original array is not affected.
https://api.jquery.com/jQuery.grep/
var link = $(".sortable[data-sort-column=" + someInput.value + "]");
Have you looked at jQuery's each?
You might format it more like:
myCollection.each(function( item ) { ... });
doStuff(document.getElementById("myCircle1" "myCircle2" "myCircle3" "myCircle4"));
This doesn't work, so do I need a comma or semi-colon to make this work?
document.getElementById() only supports one name at a time and only returns a single node not an array of nodes. You have several different options:
You could implement your own function that takes multiple ids and returns multiple elements.
You could use document.querySelectorAll() that allows you to specify multiple ids in a CSS selector string .
You could put a common class names on all those nodes and use document.getElementsByClassName() with a single class name.
Examples of each option:
doStuff(document.querySelectorAll("#myCircle1, #myCircle2, #myCircle3, #myCircle4"));
or:
// put a common class on each object
doStuff(document.getElementsByClassName("circles"));
or:
function getElementsById(ids) {
var idList = ids.split(" ");
var results = [], item;
for (var i = 0; i < idList.length; i++) {
item = document.getElementById(idList[i]);
if (item) {
results.push(item);
}
}
return(results);
}
doStuff(getElementsById("myCircle1 myCircle2 myCircle3 myCircle4"));
This will not work, getElementById will query only one element by time.
You can use document.querySelectorAll("#myCircle1, #myCircle2") for querying more then one element.
ES6 or newer
With the new version of the JavaScript, you can also convert the results into an array to easily transverse it.
Example:
const elementsList = document.querySelectorAll("#myCircle1, #myCircle2");
const elementsArray = [...elementsList];
// Now you can use cool array prototypes
elementsArray.forEach(element => {
console.log(element);
});
How to query a list of IDs in ES6
Another easy way if you have an array of IDs is to use the language to build your query, example:
const ids = ['myCircle1', 'myCircle2', 'myCircle3'];
const elements = document.querySelectorAll(ids.map(id => `#${id}`).join(', '));
No, it won't work.
document.getElementById() method accepts only one argument.
However, you may always set classes to the elements and use getElementsByClassName() instead. Another option for modern browsers is to use querySelectorAll() method:
document.querySelectorAll("#myCircle1, #myCircle2, #myCircle3, #myCircle4");
I suggest using ES5 array methods:
["myCircle1","myCircle2","myCircle3","myCircle4"] // Array of IDs
.map(document.getElementById, document) // Array of elements
.forEach(doStuff);
Then doStuff will be called once for each element, and will receive 3 arguments: the element, the index of the element inside the array of elements, and the array of elements.
getElementByID is exactly that - get an element by id.
Maybe you want to give those elements a circle class and getElementsByClassName
document.getElementById() only takes one argument. You can give them a class name and use getElementsByClassName() .
Dunno if something like this works in js, in PHP and Python which i use quite often it is possible.
Maybe just use for loop like:
function doStuff(){
for(i=1; i<=4; i++){
var i = document.getElementById("myCiricle"+i);
}
}
Vulgo has the right idea on this thread. I believe his solution is the easiest of the bunch, although his answer could have been a little more in-depth. Here is something that worked for me. I have provided an example.
<h1 id="hello1">Hello World</h1>
<h2 id="hello2">Random</h2>
<button id="click">Click To Hide</button>
<script>
document.getElementById('click').addEventListener('click', function(){
doStuff();
});
function doStuff() {
for(var i=1; i<=2; i++){
var el = document.getElementById("hello" + i);
el.style.display = 'none';
}
}
</script>
Obviously just change the integers in the for loop to account for however many elements you are targeting, which in this example was 2.
The best way to do it, is to define a function, and pass it a parameter of the ID's name that you want to grab from the DOM, then every time you want to grab an ID and store it inside an array, then you can call the function
<p id="testing">Demo test!</p>
function grabbingId(element){
var storeId = document.getElementById(element);
return storeId;
}
grabbingId("testing").syle.color = "red";
You can use something like this whit array and for loop.
<p id='fisrt'>??????</p>
<p id='second'>??????</p>
<p id='third'>??????</p>
<p id='forth'>??????</p>
<p id='fifth'>??????</p>
<button id="change" onclick="changeColor()">color red</button>
<script>
var ids = ['fisrt','second','third','forth','fifth'];
function changeColor() {
for (var i = 0; i < ids.length; i++) {
document.getElementById(ids[i]).style.color='red';
}
}
</script>
For me worked flawles something like this
doStuff(
document.getElementById("myCircle1") ,
document.getElementById("myCircle2") ,
document.getElementById("myCircle3") ,
document.getElementById("myCircle4")
);
Use jQuery or similar to get access to the collection of elements in only one sentence. Of course, you need to put something like this in your html's "head" section:
<script type='text/javascript' src='url/to/my/jquery.1.xx.yy.js' ...>
So here is the magic:
.- First of all let's supose that you have some divs with IDs as you wrote, i.e.,
...some html...
<div id='MyCircle1'>some_inner_html_tags</div>
...more html...
<div id='MyCircle2'>more_html_tags_here</div>
...blabla...
<div id='MyCircleN'>more_and_more_tags_again</div>
...zzz...
.- With this 'spell' jQuery will return a collection of objects representing all div elements with IDs containing the entire string "myCircle" anywhere:
$("div[id*='myCircle']")
This is all! Note that you get rid of details like the numeric suffix, that you can manipulate all the divs in a single sentence, animate them... Voilá!
$("div[id*='myCircle']").addClass("myCircleDivClass").hide().fadeIn(1000);
Prove this in your browser's script console (press F12) right now!
As stated by jfriend00,
document.getElementById() only supports one name at a time and only returns a single node not an array of nodes.
However, here's some example code I created which you can give one or a comma separated list of id's. It will give you one or many elements in an array. If there are any errors, it will return an array with an Error as the only entry.
function safelyGetElementsByIds(ids){
if(typeof ids !== 'string') return new Error('ids must be a comma seperated string of ids or a single id string');
ids = ids.split(",");
let elements = [];
for(let i=0, len = ids.length; i<len; i++){
const currId = ids[i];
const currElement = (document.getElementById(currId) || new Error(currId + ' is not an HTML Element'));
if(currElement instanceof Error) return [currElement];
elements.push(currElement);
};
return elements;
}
safelyGetElementsByIds('realId1'); //returns [<HTML Element>]
safelyGetElementsByIds('fakeId1'); //returns [Error : fakeId1 is not an HTML Element]
safelyGetElementsByIds('realId1', 'realId2', 'realId3'); //returns [<HTML Element>,<HTML Element>,<HTML Element>]
safelyGetElementsByIds('realId1', 'realId2', 'fakeId3'); //returns [Error : fakeId3 is not an HTML Element]
If, like me, you want to create an or-like construction, where either of the elements is available on the page, you could use querySelector. querySelector tries locating the first id in the list, and if it can't be found continues to the next until it finds an element.
The difference with querySelectorAll is that it only finds a single element, so looping is not necessary.
document.querySelector('#myCircle1, #myCircle2, #myCircle3, #myCircle4');
here is the solution
if (
document.getElementById('73536573').value != '' &&
document.getElementById('1081743273').value != '' &&
document.getElementById('357118391').value != '' &&
document.getElementById('1238321094').value != '' &&
document.getElementById('1118122010').value != ''
) {
code
}
You can do it with document.getElementByID Here is how.
function dostuff (var here) {
if(add statment here) {
document.getElementById('First ID'));
document.getElementById('Second ID'));
}
}
There you go! xD
I need to get the ID of an element but the value is dynamic with only the beginning of it is the same always.
Heres a snippet of the code.
<form class="form-poll" id="poll-1225962377536" action="/cs/Satellite">
The ID always starts with poll- then the numbers are dynamic.
How can I get the ID using just JavaScript and not jQuery?
You can use the querySelector for that:
document.querySelector('[id^="poll-"]').id;
The selector means: get an element where the attribute [id] begins with the string "poll-".
^ matches the start
* matches any position
$ matches the end
jsfiddle
Try this.
function getElementsByIdStartsWith(container, selectorTag, prefix) {
var items = [];
var myPosts = document.getElementById(container).getElementsByTagName(selectorTag);
for (var i = 0; i < myPosts.length; i++) {
//omitting undefined null check for brevity
if (myPosts[i].id.lastIndexOf(prefix, 0) === 0) {
items.push(myPosts[i]);
}
}
return items;
}
Sample HTML Markup.
<div id="posts">
<div id="post-1">post 1</div>
<div id="post-12">post 12</div>
<div id="post-123">post 123</div>
<div id="pst-123">post 123</div>
</div>
Call it like
var postedOnes = getElementsByIdStartsWith("posts", "div", "post-");
Demo here: http://jsfiddle.net/naveen/P4cFu/
querySelectorAll with modern enumeration
polls = document.querySelectorAll('[id ^= "poll-"]');
Array.prototype.forEach.call(polls, callback);
function callback(element, iterator) {
console.log(iterator, element.id);
}
The first line selects all elements in which id starts ^= with the string poll-.
The second line evokes the enumeration and a callback function.
Given that what you want is to determine the full id of the element based upon just the prefix, you're going to have to do a search of the entire DOM (or at least, a search of an entire subtree if you know of some element that is always guaranteed to contain your target element). You can do this with something like:
function findChildWithIdLike(node, prefix) {
if (node && node.id && node.id.indexOf(prefix) == 0) {
//match found
return node;
}
//no match, check child nodes
for (var index = 0; index < node.childNodes.length; index++) {
var child = node.childNodes[index];
var childResult = findChildWithIdLike(child, prefix);
if (childResult) {
return childResult;
}
}
};
Here is an example: http://jsfiddle.net/xwqKh/
Be aware that dynamic element ids like the ones you are working with are typically used to guarantee uniqueness of element ids on a single page. Meaning that it is likely that there are multiple elements that share the same prefix. Probably you want to find them all.
If you want to find all of the elements that have a given prefix, instead of just the first one, you can use something like what is demonstrated here: http://jsfiddle.net/xwqKh/1/
I'm not entirely sure I know what you're asking about, but you can use string functions to create the actual ID that you're looking for.
var base = "common";
var num = 3;
var o = document.getElementById(base + num); // will find id="common3"
If you don't know the actual ID, then you can't look up the object with getElementById, you'd have to find it some other way (by class name, by tag type, by attribute, by parent, by child, etc...).
Now that you've finally given us some of the HTML, you could use this plain JS to find all form elements that have an ID that starts with "poll-":
// get a list of all form objects that have the right type of ID
function findPollForms() {
var list = getElementsByTagName("form");
var results = [];
for (var i = 0; i < list.length; i++) {
var id = list[i].id;
if (id && id.search(/^poll-/) != -1) {
results.push(list[i]);
}
}
return(results);
}
// return the ID of the first form object that has the right type of ID
function findFirstPollFormID() {
var list = getElementsByTagName("form");
var results = [];
for (var i = 0; i < list.length; i++) {
var id = list[i].id;
if (id && id.search(/^poll-/) != -1) {
return(id);
}
}
return(null);
}
You'll probably have to either give it a constant class and call getElementsByClassName, or maybe just use getElementsByTagName, and loop through your results, checking the name.
I'd suggest looking at your underlying problem and figure out a way where you can know the ID in advance.
Maybe if you posted a little more about why you're getting this, we could find a better alternative.
You use the id property to the get the id, then the substr method to remove the first part of it, then optionally parseInt to turn it into a number:
var id = theElement.id.substr(5);
or:
var id = parseInt(theElement.id.substr(5));
<form class="form-poll" id="poll-1225962377536" action="/cs/Satellite" target="_blank">
The ID always starts with 'post-' then the numbers are dynamic.
Please check your id names, "poll" and "post" are very different.
As already answered, you can use querySelector:
var selectors = '[id^="poll-"]';
element = document.querySelector(selectors).id;
but querySelector will not find "poll" if you keep querying for "post": '[id^="post-"]'
If you need last id, you can do that:
var id_list = document.querySelectorAll('[id^="image-"]')
var last_id = id_list.length
alert(last_id)