迭代document.getElementsByClassName

Question

Hi guys i'm trying to iterate a getElementsByClassName in this way:

var i;
for (i = 0; i < 20; i++) { 
if (document.getElementsByClassName("available")[i]==="undefined"){}
else{
 document.getElementsByClassName("available")[i].click();  }



}

if i do it in chrome console it works fine , but when i run it trough my chrome extension it says read property 'click' of undefined , do you know how i can solve?

Answer 1

Try something like this

 var available = document.getElementsByClassName("available"); //collection of elements matching the query //Loop collection. //Skips loop if the available collection is empty for (var i = 0; i < available.length; i++) { available[i].click(); } 

Answer 2

Your if statement isn't working as you're not checking to see whether the type of the target element is undefined. Try this instead -

document.getElementsByClassName("available")[i]===undefined