# KOS_OP_ITEM_VAR_INPLACE
- **Style**: EXTRA (OPCOUNT, VAR, NOARG, NOARG).
- **Stack**: `[..., obj, v0 .. v_{n-1}] → [...]`. Reduce obj[key] in place with the count values left to right and store it back with the object on the stack and the key resolved by name.
- **Cache**: none; a VAR row survives lowering only for a name with no fast slot.
- **Compiler form:** Shaped by **`compile/inplace-item`** when OBJ is a symbol or KEY is a feeder and a value is not, so the fold could not reach the named operands. May lower to **ITEM_FAST_INPLACE**.
- **Implementation**: `koskari/lib/opcode/ITEM_VAR_INPLACE.c`