Question

var toBeHidden_letter = document.getElementsByClassName('doc_direction');
for(var i = 0; i < 10; i++) {
    toBeHidden_letter[i].style.display = 'block';
    alert('i = '+i);
}  

I only have 2 alerts. why?

Edited : I have 10 elements of class = ‘doc_direction’ in my HTML.

Answer 1

I think you need :

var toBeHidden_letter = document.getElementsByClassName('doc_direction');
for(var i = 0; i < toBeHidden_letter.length; i++) {
    toBeHidden_letter[i].style.display = 'block';
    alert('i = '+i);
}