constructor() {
      super();
      this._filteredItems = [];
      this._initialRendering = true;
      this._itemFocused = false;
      this._autocomplete = false;
      this._isKeyNavigation = false;
      this._lastValue = "";
      this._selectionPerformed = false;
      this._selectedItemText = "";
      this._userTypedValue = "";
    }
@class

<h3 class="comment-api-title">Overview</h3>

The <code>ui5-combobox</code> component represents a drop-down menu with a list of the available options and a text input field to narrow down the options.

It is commonly used to enable users to select an option from a predefined list.

<h3>Structure</h3>
The <code>ui5-combobox</code> consists of the following elements:

<ul>
<li> Input field - displays the selected option or a custom user entry. Users can type to narrow down the list or enter their own value.</li>
<li> Drop-down arrow - expands\collapses the option list.</li>
<li> Option list - the list of available options.</li>
</ul>

<h3>Keyboard Handling</h3>

The <code>ui5-combobox</code> provides advanced keyboard handling.
<br>

<ul>
<li>[F4], [ALT]+[UP], or [ALT]+[DOWN] - Toggles the picker.</li>
<li>[ESC] - Closes the picker, if open. If closed, cancels changes and reverts the typed in value.</li>
<li>[ENTER] or [RETURN] - If picker is open, takes over the currently selected item and closes it.</li>
<li>[DOWN] - Selects the next matching item in the picker.</li>
<li>[UP] - Selects the previous matching item in the picker.</li>
<li>[PAGEDOWN] - Moves selection down by page size (10 items by default).</li>
<li>[PAGEUP] - Moves selection up by page size (10 items by default). </li>
<li>[HOME] - If focus is in the ComboBox, moves cursor at the beginning of text. If focus is in the picker, selects the first item.</li>
<li>[END] - If focus is in the ComboBox, moves cursor at the end of text. If focus is in the picker, selects the last item.</li>
</ul>


<h3>ES6 Module Import</h3>

<code>import "@ui5/webcomponents/dist/ComboBox";</code>


@constructor
@author SAP SE
@alias sap.ui.webc.main.ComboBox
@extends sap.ui.webc.base.UI5Element
@tagname ui5-combobox
@appenddocs sap.ui.webc.main.ComboBoxItem sap.ui.webc.main.ComboBoxGroupItem
@public
@since 1.0.0-rc.6