ParentNode.childElementCount - Web APIs 编辑

The ParentNode.childElementCount read-only property returns an unsigned long representing the number of child elements of the given element.

This property was initially defined in the ElementTraversal pure interface. As this interface contained two distinct set of properties, one aimed at Node that have children, one at those that are children, they have been moved into two separate pure interfaces, ParentNode and ChildNode. In this case, childElementCount moved to ParentNode. This is a fairly technical change that shouldn't affect compatibility.

Syntax

var count = node.childElementCount;

count

The return value, which is an unsigned long (an integer) type.

node

An object representing a Document, DocumentFragment, or Element.

Example

var foo = document.getElementById('foo');
if (foo.childElementCount > 0) {
  // Do something
}

Polyfill for IE8 & IE9 & Safari

This property is completely unsupported prior to IE9. In IE9 and Safari, it is unsupported in the Document and DocumentFragment objects.

;(function(constructor) {
  if (constructor &&
      constructor.prototype &&
      constructor.prototype.childElementCount == null) {
    Object.defineProperty(constructor.prototype, 'childElementCount', {
      get: function() {
        var i = 0, count = 0, node, nodes = this.childNodes;
        while (node = nodes[i++]) {
          if (node.nodeType === 1) count++;
        }
        return count;
      }
    });
  }
})(window.Node || window.Element);

Specifications

Browser compatibility

BCD tables only load in the browser

See also

• The ParentNode and ChildNode pure interfaces.
• Object types implementing this pure interface: Document, Element, and DocumentFragment.