typeof给了我一个数字，但同一变量的console.log给了我NAN如何解决这个问题

Question

store = {
bags: {
inventory: 30,
cost: 12.99
},
pen: {
inventory: 30,
cost: 34.23
}
};
const buy = (x, y) => {
return new Promise((resolve, reject) => {
if (x === "bags" && y >= 1 && y < 30) {
resolve(parseInt(y * store.bags.cost));
} else {
reject("out of order");
}
});
};
const buy1 = (x, y) => {
return new Promise((resolve, reject) => {
if (x === "pen" && y >= 1 && y < 30) {
resolve(parseInt(y * store.pen.cost));
} else {
reject("out of order");
}
});
};
const totalBag = [];
const totalPen = [];
parseInt(totalBag.push(buy("bags", 12)));
parseInt(totalPen.push(buy1("pen", 12)));
const total = () => {
return new Promise((resolve, reject) => {
if (x === "pen" && y >= 1 && y < 30) {
resolve(parseInt(y * store.pen.cost));
} else {
reject("out of order");
}
});
};
totalsum = 0;
totalsum = parseInt(totalBag) + parseInt(totalPen);
console.log(typeof totalsum);
console.log(totalsum);

Answer 1

这是因为typeof NaN = number，奇怪但真实的

Answer 2

**

非常感谢你的评论，我终于明白了

**存储=｛

bags : { 
inventory : 30,
cost : 12.99
},
pen : {
inventory : 30,
cost : 34.23
}

}；

const totalBag=[]；

const totalPen=[]；

const buy=(x，y，(=>｛

return new Promise((resolve, reject)=>{
if(x ==='bags'  && y >= 1 && y< 30 ){
resolve(totalBag.push(parseInt((y*store.bags.cost))));
}else { reject ('out of order');}; 
});

}；const buy1=(x1，y1(=>｛

return new Promise((resolve, reject)=>{
if(x1 ==='pen'  && y1 >= 1 && y1< 30 ){
resolve(totalPen.push((parseInt((y1*store.pen.cost)))));
}else { reject ('out of order');}; 
}); 

}；

const amtBag=买入('bags'，10(；

const amtPen=buy1('pen'，10(；

设tbag=数量(totalBag(；

设tpen=数字(totalPen(；

let TotalPurchase=console.log(tbag+tpen(；