到底什么时候使用async-await然后呢？

对此我感到非常困惑。我要求您澄清一下概念。

I am very confused about this. I request you to clarify the concept.

请考虑以下情形：

案例1：

int number = 0; 

void calculate() {
   number = number + 2;
   print(number);
}

我知道这很好。 2将显示在终端上。

I know this works just fine. "2" will be printed on the terminal.

但是我为什么不应该使用 async - await 在这里，像这样：

But why shouldn't I use async-await here, like this:

 int number = 0; 

void calculate() async {

 void addition() async {
   number = number + 2;
  }

 await addition();
   print(number);
}

在我看来这很合逻辑，因为 print（number ）应该等待 number = number + 2 完成。为什么这没有必要？ dart如何知道要先执行哪个操作？

This seems logical to me, since print(number) should wait for number = number + 2 to finish. Why isn't this necessary? How does dart know which operation to execute first?

如何确保在 number = =之前不执行 print（number）数字+ 2 并在终端上打印 0？

How is it ensured that print(number) isn't executed before number = number + 2 and "0" is printed on the terminal?

Does the sequence in which we write these operations in the function matter?

案例2：
考虑我正在互动的情况与 SQFLite 数据库和获取的值相互依赖。

Case 2: Consider the case where I am interacting with SQFLite database and values fetched depend on each other.

注意： number1 ， number2 ， number3 在以下 function 被调用。

Note: number1, number2, number3 will still have values before the following function is called.

void getValues() async {

  void calculate1() {
   number1 = await db.getNumber1(10);
  }

  void calculate2() {
   number2 = await db.getNumber2(number1);
  }

  await calculate1().then((_) async {
    await calculate2().then((_) async {
     number3 = await db.getNumber3(number2);
    });
  });

}

我的应用程序中有很多这类功能我到处都在做

I have a lot of these types of functions in my app and I am doing this everywhere.

我有点偏执，想知道 number1 和 number2的旧值在 getNumber2（）和 getNumber3（）中作为参数 ，那么我就注定了。

I am kind of paranoid, thinking if old values of number1and number2 are taken as a parameter in getNumber2() and getNumber3() respectively, then I'll be doomed.