How to select all elements in the DOM with same class?

Question

Im trying to implement multilanguage support to a website and for that I need to select all elements that have class="lang" attribute. This is how my Js code looks like

$(function(){
    var language = localStorage.getItem('language');
    if(language !== null){
        //this does not work
        $(document).find('.lang').each(function (index, element) {
            if($(this).attr('placeholder')!=null){
                //change placeholder text
            }
            $(this).text(arrLang[language][$(this).attr('key')]);
        });
    }

    //this works
    $(document).on('click','.translate',function () {
        var lang = $(this).attr('id');
        $(document).find('.lang').each(function (index, element) {
            if($(this).attr('placeholder')!=null){
                //change placeholder text
            }
            $(this).text(arrLang[lang][$(this).attr('key')]);
            localStorage.setItem('language',lang);
        });
    });
});

And this is the html code where Im trying to test this out

<div class="navbar navbar-default navbar-static-top">
    <div class="container-fluid">
        <div class="navbar-header">
            <div class="navbar-brand">
                <img alt="brand" src="../img/th-logo.png" height="25px" width="60px" href="Startsite.jsp">
            </div>
        </div>
        <div class="navbar-brand">Studienlaufplan </div>
        <button class="navbar-toggle" data-toggle="collapse" data-target=".navHeaderCollapse">
            <span class="icon-bar"></span>
            <span class="icon-bar"></span>
            <span class="icon-bar"></span>
        </button>
        <div class="collapse navbar-collapse navHeaderCollapse">
            <ul class="nav navbar-nav navbar-right">
                <li><a href="../Startsite.jsp" class="lang" key="tasks" >Aufgaben</a> </li>
                <li><a href="../Account.jsp" class="lang" key="account" >Konto</a> </li>
                <li><a href="Canal.jsp" class="lang" key="cannals">Kanäle</a> </li>
                <li><a href="Settings.jsp" class="lang" key="settings">Einstellugen</a> </li>
                <li class="dropdown">
                    <a href="#" class="lang dropdown-toggle" data-toggle="dropdown" role="button" aria-haspopup="true" aria-expanded="false" key="language">Sprache</a>
                    <ul class="dropdown-menu">
                        <li><a href="#" class="translate" id="de">Deutsch</a></li>
                        <li><a href="#" class="translate" id="en">English</a></li>
                    </ul>
                </li>
                <li><a href="/Controller/Logout" class="lang" key="logout">Abmelden</a></li>
            </ul>
        </div>
    </div>
</div>

Im confused about jquery selectors and actually dont know how to use them well. Any help will be appreciated

Answer 1

To get all elements with the specified class name, Try document.getElementsByClassName:-

var x = document.getElementsByClassName("className");

The getElementsByClassName() method is not supported in Internet Explorer 8 and earlier versions.

function myFunction() {
  var x = document.getElementsByClassName("example");
  x[0].innerHTML = "Hello World!";
  x[1].innerHTML = "my first code snippet"
}

<div class="example">First div element with class="example".</div>

<div class="example">Second div element with class="example".</div>

<button onclick="myFunction()">Try it</button>

try it yourself here.

Answer 2

This should do the trick:

$(".lang").each(function() {
    const $lang = $(this);
    // translate this item's text
});