$VAR1 = 'foo';
$VAR2 = [
          [
            'foo01',
            'foo02'
          ],
          [
            'foo11',
            'foo12'
          ]
        ];
$VAR3 = 'bar';
$VAR4 = [
          [
            'bar01',
            'bar02'
          ],
          [
            'bar11',
            'bar12'
          ]
        ];