set selectedIndex(value) {
    if (Number.isInteger(value) && this.options[value]) {
      const elem = this.options[value];
      this.value = elem.getAttribute('value');
      this.state.selectedIndex = value;
    }
  }
/**
   * Set the selected option by index
   * @param {number} value the index to use
   */
Set the selected option by index
@param {number} value the index to use
Set the selected option by index @param { number } value the index to use
set selectedIndex(value) {
    if (Number.isInteger(value) && this.options[value]) {
      const elem = this.options[value];
      this.value = elem.getAttribute('value');
      this.state.selectedIndex = value;
    }
  }
set selectedIndex ( value ) { if ( Number . isInteger ( value ) && this . options [ value ] ) { const elem = this . options [ value ] ; this . value = elem . getAttribute ( 'value' ) ; this . state . selectedIndex = value ; } }
Set the selected option by index
 @param {number} value the index to use
Set the selected option by index @param { number } value the index to use