It's really hard for me to guess your intention. On one hand you are declaring that both of those a and b are public (no major underscore inside their names) so I should really theoretically be permitted to entry/mutate (get/set) equally. But Then you certainly specify an explicit mutator only https://smartworlddeveloper.co.in/smart-world-69-sector-69-gurgaon-a-new-benchmark-in-urban-luxury-living/