"Ngga" is abbreviation for "Nggak" and abbreviation for "Enggak" is simple use for "Tidak" or "No" in English which usually used by mostly people in Indonesia for non-formal conversation
Jika gw punya 100 Rupiah setiap kasus dimana orang2 outdonesia salah ngira "ngga" sebagai rasis, gw kira2 punya 200 rupiah. Ngga/nggak/ga/moh/tidak banyak, tapi lucu aja terjadi dua kali.