Attempt to hide div if page title = "x"

Question

I am trying to do tweeking wordpress themes and hide specific divonly on certain pages with some javascript, the code I came up with is:

if(document.getElementsByClassName("page-title") === "NEW ARRIVALS"){
    document.getElementById("pull_9").style.visibility="hidden";
}else if(document.getElementsByClassName("page-title") === "SALE"){
    document.getElementById("pull_9").style.visibility="hidden";
}else{
    document.getElementById("pull_9").style.visibility="visible";
};

but it does not work, I know that getElementByClassName () is not yet supported, but it will fulfill these requirements.

Can anyone understand why this is not working? maybe something is very simple (I'm new to javascript), but I cannot theoretically understand why it should not work.

Answer 1

Content NEW ARRIVALSand SALEthese items?

page-title <title>,

document.querySelector('title').textContent

page-title ONE , :

document.querySelector('.page-title').textContent

...

var elem = document.getElementsByClassName('page-title');

for (var i = 0, len = elem.length; i < len; i++) {

  if (elem[i].textContent === 'NEW ARRIVALS' || 
      elem[i].textContent === 'SALE') {
    document.getElementById('pull_9').style.visibility = 'hidden'; 
    break;     
  }
} 

....

for (var i = 0, len = elem.length; i < len; i++) {

  if (elem[i].textContent.match(/NEW ARRIVALS|SALE/)) {
    document.getElementById("pull_9").style.visibility = 'hidden';
    break;    
  }
}

, .

, ... , ,

if (document.querySelector('.page-title').textContent.match(/NEW ARRIVALS|SALE/)) {
  document.getElementById('pull_9').style.visibility = 'hidden'; 
}

Answer 2

document.getElementsByClassName . Array.filter ... .

var set = document.getElementsByClassName('whatever');

var item = document.getElementsByClassName('whatever')[0];

https://developer.mozilla.org/en-US/docs/Web/API/document.getElementsByClassName

, getElementsByClassName :

http://caniuse.com/#search=getelementsbyclassname

Answer 3

jQuery , :contains toggle

var show = !$('.page-title:contains(NEW ARRIVALS), .page-title:contains(SALE)')
            .length; 
$('#pull_9').toggle(show);

.