document.getElementsByClassName
returns an array of matched elements. In your case, an array of elements with the class name of fc_card-container
. Your next step would be to iterate over the elements and assign an event listener to each or select a specific one using an index (starting with 0).
Assign a click to all
var cards = document.getElementsByClassName('fc_card-container');
for(var i = 0; i < cards.length; i++){ //iterate through each card
cards[i].onclick = function() {alert('It works!');};
};
Assign a click to a single card (eg: 3rd card)
var cards = document.getElementsByClassName('fc_card-container');
cards[2].onclick = function() {alert('It works!');}; //0,1,2