It's Tough for me to guess your intention. On one hand you're declaring that the two a and b are public (no primary underscore inside their names) so I should really theoretically be allowed to access/mutate (get/set) the two. But Then you really specify an explicit mutator only for a, https://aipljoysdistrict.in/aipl-joy-district-sector-88-gurgaon-a-landmark-of-commercial-brilliance-with-lifestyle-innovation/