Remove Widows from text in WordPress

widont.php

/**
 * Make last space in a sentence a non breaking space to prevent typographic widows.
 *
 * @param type $str
 * @return string
 */
function theme_widont( $str = '' ) {

	// Strip spaces.
	$str = trim( $str );
	// Find the last space.
	$space = strrpos( $str, ' ' );

	// If there's a space then replace the last on with a non breaking space.
	if ( false !== $space ) {
		$str = substr( $str, 0, $space ) . ' ' . substr( $str, $space + 1 );
	}

	// Return the string.
	return $str;

}