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JavaScript AJAX Basics (retiring) AJAX Concepts A Simple AJAX Example

Hello World
Hello World
12,904 Points
Posted by Hello World
Hello World
12,904 Points

select the button using getElementsByTagName and it doesn't work?

My code is as below, i simply changed "document.getElementById("load")" to "getElementsByTagName("button")", it doesn't work. it shows "cannot set display of undefined" in the console.

 var xhr = new XMLHttpRequest();
    xhr.onreadystatechange = function() {
      if(xhr.readyState === 4) {
        document.getElementById("ajax").innerHTML = xhr.responseText;
      }
    };
    xhr.open("GET", "sidebar.html");
    function sendAjax() {
      xhr.send();
      document.getElementsByTagName("button").style.display = "none";
    }

1 Answer

Jake Adams
Jake Adams
1,608 Points
Jake Adams
Jake Adams
1,608 Points

My JavaScript and DOM manipulation skills are rusty, but I believe you have to loop over the results of the getElementsByTagName before calling .style. That method returns an array of elements and an array has no style property.

You can optionally just access the first element in that array like

document.getElementsByTagName("button")[0].style.display = "none";

That's making an assumption that the first button on the page is the one you want to hide.

Hello World
Hello World
12,904 Points
Hello World
Hello World
12,904 Points

yes, your are right, thank you.