Document: getElementsByTagNameNS() method

{{APIRef("DOM")}}

Returns a list of elements with the given tag name belonging to the given namespace. The complete document is searched, including the root node.

Syntax

getElementsByTagNameNS(namespace, name)

Parameters

namespace
- : The namespace URI of elements to look for (see {{domxref("Element.namespaceURI", "element.namespaceURI")}} ).
name
- : Either the local name of elements to look for or the special value *, which matches all elements (see {{domxref("Element.localName", "element.localName")}} ).
  
  [!NOTE] Unlike {{domxref("document.getElementsByTagName()")}} , the parameters for getElementsByTagNameNS() are case-sensitive.

Return value

A live {{DOMxRef("HTMLCollection")}} of found elements in the order they appear in the tree.

Examples

In the following example getElementsByTagNameNS starts from a particular parent element, and searches top-down recursively through the DOM from that parent element, looking for child elements matching the tag name parameter.

Note that when the node on which getElementsByTagName is invoked is not the document node, in fact the {{domxref("element.getElementsByTagNameNS")}} method is used.

To use the following example, just copy/paste it into a new file saved with the .xhtml extension.

<html lang="en" xmlns="http://www.w3.org/1999/xhtml">
  <head>
    <title>getElementsByTagNameNS example</title>

    <script>
      function getAllParaElems() {
        const allParas = document.getElementsByTagNameNS(
          "http://www.w3.org/1999/xhtml",
          "p",
        );
        const num = allParas.length;
        alert(`There are ${num} &lt;p&gt; elements in this document`);
      }

      function div1ParaElems() {
        const div1 = document.getElementById("div1");
        const div1Paras = div1.getElementsByTagNameNS(
          "http://www.w3.org/1999/xhtml",
          "p",
        );
        const num = div1Paras.length;
        alert(`There are ${num} &lt;p&gt; elements in div1 element`);
      }

      function div2ParaElems() {
        const div2 = document.getElementById("div2");
        const div2Paras = div2.getElementsByTagNameNS(
          "http://www.w3.org/1999/xhtml",
          "p",
        );
        const num = div2Paras.length;
        alert(`There are ${num} &lt;p&gt; elements in div2 element`);
      }
    </script>
  </head>

  <body style="border: solid green 3px">
    <p>Some outer text</p>
    <p>Some outer text</p>

    <div id="div1" style="border: solid blue 3px">
      <p>Some div1 text</p>
      <p>Some div1 text</p>
      <p>Some div1 text</p>

      <div id="div2" style="border: solid red 3px">
        <p>Some div2 text</p>
        <p>Some div2 text</p>
      </div>
    </div>

    <p>Some outer text</p>
    <p>Some outer text</p>

    <button onclick="getAllParaElems();">
      Show all p elements in document
    </button>
    <br />

    <button onclick="div1ParaElems();">
      Show all p elements in div1 element
    </button>
    <br />

    <button onclick="div2ParaElems();">
      show all p elements in div2 element
    </button>
  </body>
</html>

Specifications

{{Specifications}}

Browser compatibility

{{Compat}}

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