/replaceitem: 把物品放进方块或实体物品栏的指定栏位，比如箱子的某个格子或盔甲栏位。
语法
<尖括号> 内为必填，[方括号] 内为可选。 /replaceitem 有 4 种写法：
/replaceitem <block: replaceitemblock> <position: position> <slotType: blockequipmentslot> <slotId: int> <itemName: item> [amount: int] [data: int] [components: json_object]
/replaceitem <entity: replaceitementity> <target: selection> <slotType: entityequipmentslot> <slotId: int> <itemName: item> [amount: int] [data: int] [components: json_object]
/replaceitem <block: replaceitemblock> <position: position> <slotType: blockequipmentslot> <slotId: int> <oldItemHandling: replacemode> <itemName: item> [amount: int] [data: int] [components: json_object]
/replaceitem <entity: replaceitementity> <target: selection> <slotType: entityequipmentslot> <slotId: int> <oldItemHandling: replacemode> <itemName: item> [amount: int] [data: int] [components: json_object]