Get the data in session using the key.
The $flash flag does either flash the session data or not.

@param  string  $key
@param  boolean $flash
@return mixed
422748
public static function get($key, $flash = false)
    {
        if (isset($_SESSION[$key]))
        {
            $session_value = $_SESSION[$key];
            if ($flash)
            {
                unset($_SESSION[$key]);
            }
            return $session_value;
        }

        return null;
    }
305182
public function get($key) {
        if (isset($this->_session->{$key})) {
            return $this->_session->{$key};
        }
        return null;
    }
329638
public static function getFlash($key)
    {
        $var = Security::getInstance()->getFlash($key);
        Security::getInstance()->setFlash($key, null);
        return $var;
    }
757927
public function get($key)
    {
        $filename = $this->_filename($key);
        if (!file_exists($filename)) {
            return false;
        }

        $tmp_value = file_get_contents($filename);
        $expire    = (int) substr($tmp_value, 13, 24);

        // echo time()."<br />\n";
        // echo $expire."<br />\n";
        // echo substr($tmp_value,23);exit;

        if ($expire != 0 && time() < $expire) {
            return unserialize(substr($tmp_value, 23));
        } else {
            return false;
        }
    }
57996
public function get(string $key)
    {
        $key = $this->getNamespacedKey($key);

        return $this->session->get($key);
    }
821646
public function get($key)
    {
        return isset($this->vars[$key]) ? $this->vars[$key] : false;
    }
1041258
public function get_data($key) {
        if (isset($this->data->$key)) {
            return $this->data->$key;
        }
        return null;
    }
850702
public function getData($key = null)
    {
        if (!$key) {
            return $this->data;
        } else if ($this->hasKey($key)) {
            return $this->data[$key] ?? null;
        }

        return null;
    }
19889
public function getComplexFlash($key){

        if(!isset($this->flash[$key])){
            return false;
        }//if

        return unserialize($this->flash[$key]);

    }
240730
public static function getData($key) {
		if(!isset(self::$output_data[$key]))
			return false;

		return self::$output_data[$key];
	}
15311
public function get( $key ) {
		$key = sanitize_key( $key );

		return isset( $_SESSION[ $key ] ) ? json_decode( $_SESSION[ $key ] ) : false;
	}
99230
public function getSession($key = null)
    {
        $user = $this->session->get('user', array());

        if (isset($key)) {
            return gplcart_array_get($user, $key);
        }

        return $user;
    }
223815
public function getStorageValue($key = false) {
        $key = (!$key ? $this->name."InputResult" : $key);
        $storedData = $this->storedFormData;
        if (empty($storedData)) {
            $storageContainer = $this->getStorageContainer();
            if ($storageContainer->offsetExists($key))
                $storedData = $storageContainer->get($key);
            else return false;

        }
        return $storedData;
    }
835214
public static function flash($key, $string = null)
    {
        if ((self::exists($key))) {
            $session = self::get($key);
            self::delete($key);
            return $session;
        }

        return false;
    }
492486
public function getSessionItem($key)
    {
        return isset($this->session[$key]) ? $this->session[$key] : null;
    }
566149
static function get_value( $key ) {
		if( ! self::started() ){
			trigger_error("Session not started, cannot get_value", E_USER_WARNING );
			return null;
		}
		if( !is_array($key) ){
			$key = explode( '.', $key );
		}
		$Obj = self::$Session->Data;
		foreach( $key as $k ){
			if( !isset( $Obj[$k] ) ){
				return null;
			}
			$Obj = $Obj[$k];
		}
		return $Obj;
	}
931868
public function get($key, $default = null, $remove = false)
    {
        $data = Arr::get($_SESSION, $key, $default);

        if ($remove) {
            $this->delete($key);
        }

        return $data;
    }