php/mixins/TabIndexedElement.php
public function setTabIndex( $tabIndex ) {
		$tabIndex = preg_match( '/^-?\d+$/', $tabIndex ) ? (int)$tabIndex : null;

		if ( $this->tabIndex !== $tabIndex ) {
			$this->tabIndex = $tabIndex;
			$this->updateTabIndex();
		}

		return $this;
	}
public function setTabIndex( $tabIndex ) {
		$tabIndex = preg_match( '/^-?\d+$/', $tabIndex ) ? (int)$tabIndex : null;

		if ( $this->tabIndex !== $tabIndex ) {
			$this->tabIndex = $tabIndex;
			$this->updateTabIndex();
		}

		return $this;
	}
public function setTabIndex ( $ tabIndex ) { $ tabIndex = preg_match ( '/^-?\d+$/' , $ tabIndex ) ? ( int ) $ tabIndex : null ; if ( $ this -> tabIndex !== $ tabIndex ) { $ this -> tabIndex = $ tabIndex ; $ this -> updateTabIndex ( ) ; } return $ this ; }
Set tab index value.

@param string|int|null $tabIndex Tab index value or null for no tab index
@return $this
Set tab index value .