英文:
Updating tsconfig.json target target to "es2022" causes "Property 'xx' is used before its initialization.ts(2729)"
问题
我有很多Angular代码，其中我在其定义时分配一个属性，就像下面这样...
public errors$ = this.store$.select(fromApp.getErrors);
constructor(private store$: Store<MyState>
正如我们所看到的，store$是通过构造函数注入的。但是现在在将tsconfig.json的目标目标更改为"es2022"之后，我得到了错误
Property 'store$' is used before its initialization.ts(2729)
在声明时仍然可以分配这样的属性吗？
英文:
I have a lot of Angular code where I assign a property at its definition like the following...
public errors$ = this.store$.select(fromApp.getErrors);
constructor(private store$: Store<MyState>
As we can see store$ is injected via the constructor. But now after changing tsconfig.json target target to "es2022" I get the error
Property 'store$' is used before its initialization.ts(2729)
Are we still able to assign such properties at the declaration?
答案1
得分: 1
你实际上不确定store$是否会在errors$之前填充。
一个很好的经验法则是在声明中初始化简单属性，但每当它依赖于其他内容时，应在构造函数中进行初始化。
public errors$: Observable<Foo>;
constructor(private store$: Store<MyState>) {
this.errors$ = this.store$.select(fromApp.getErrors);
}
在这里，你可以确定`store$`在`errors$`之前被填充。
英文:
You actually don't know for sure if store$ will be filled before or after errors$.
A good rule of thumb is to initialize simple properties within the declaration, but whenever it depends on something else, do it in the constructor.
public errors$: Observable<Foo>;
constructor(private store$: Store<MyState>) {
this.errors$ = this.store$.select(fromApp.getErrors);
}
here, you're certain store$ is filled before errors$.
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