function storeid(){
    var className = document.getElementsByClassName('Jicon');
    var classnameCount = className.length;
    var IdStore = new Array();
    for(var j = 0; j < classnameCount; j++){
        IdStore = classnameCount.id[j];
    }

}

My intention is to get the id of all elements with a specific class name and store them in array.

Demo

function storeid(){
    var className = document.getElementsByClassName('Jicon');
    var classnameCount = className.length;
    var IdStore = new Array();
    for(var j = 0; j < classnameCount; j++){
        IdStore = classnameCount.id[j];
    }

}

My intention is to get the id of all elements with a specific class name and store them in array.

Demo

• javascript

5 Answers 5

You will get all the ids in IdStore array.

function storeid(){
    var className = document.getElementsByClassName('Jicon');
    var classnameCount = className.length;
    var IdStore = new Array();
    for(var j = 0; j < classnameCount; j++){
        debugger;
        IdStore.push(className[j].id);
    }
    alert(IdStore.length);
}
storeid();

<div class="Jicon" id="displayImage1">image1</div>
<div class="Jicon" id="displayImage2">image2</div>
<div class="Jicon" id="displayImage3">image3</div>
<div class="Jicon" id="displayImage4">image4</div>

I prefer querySelectorAll for this kind of things, since getElementsByClassName returns a live list, which could mess up other logic if you add/remove elements with that class.

var ids = Array.prototype.slice.call(document.querySelectorAll('.Jicon')).map(function ( element ) {
    return element.id;
});

You need few changes like following:

You must use className as it's actual array of elements which is returned by your query getElementsByClassName()

You must use .push() to add item into the array

for(var j = 0; j < classnameCount; j++){
    IdStore.push(className[j].id); // use className instead of classnameCount
}

Demo

function storeid(){
    var className = document.getElementsByClassName('Jicon');
    return className.map(function(cur){
         return cur.id
    });
}

document.write( JSON.stringify(storeid()) )

<div class="Jicon" id="displayImage1">image1</div>
<div class="Jicon" id="displayImage2">image2</div>
<div class="Jicon" id="displayImage3">image3</div>
<div class="Jicon" id="displayImage4">image4</div>

function storeid(){
    var className = document.getElementsByClassName('Jicon');
    var classnameCount = className.length;
    var IdStore = new Array();
    for(var j = 0; j < classnameCount; j++){
        IdStore[j] = className[j].id;
    }
    alert(IdStore.length);
}

here goes your code. Voila!! NOTE: remove the alert in code.