猫鼬数组拼接变为空

Question

我有一些JavaScript代码，可以从数组中拼接某些内容，但在拼接时会将其更改为null。为什么这样做？

        pPokemons.forEach(async (r, i) => {
          if(r.type == "p") {
            userdb.pokemons.push(userd.pokemons[r.value]);
            userd.pokemons.splice(r.value, 1);
          }
        })

        uPokemons.forEach(async (r, i) => {
          if(r.type == "p") {
            userd.pokemons.push(userd.pokemons[r.value]);
            userdb.pokemons.splice(r.value, 1);
          }
        })
        let user1 = await User.findOne({id: message.author.id});
        let user2 = await User.findOne({id: user.id});

        await userdb.markModified('pokemons');

        await userdb.save().catch(e => console.log(e))

        userd.markModified('pokemons');

        await userd.save().catch(e => console.log(e))