分配 Typescript 构造函数参数
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Assigning Typescript constructor parameters
提问by demo
I have interface :
我有接口：
export interface IFieldValue {
name: string;
value: string;
}
And I have class that implements it :
我有实现它的类：
class Person implements IFieldValue{
name: string;
value: string;
constructor (name: string, value: string) {
this.name = name;
this.value = value;
}
}
after reading this postI've thinking about refactoring :
阅读完这篇文章后，我开始考虑重构：
class Person implements IFieldValue{
constructor(public name: string, public value: string) {
}
}
Question : In first class I have fields which by default should be as private. In second sample I can only set them as public. Is it all correct or my understanding of default Access modifiers in TypeScript?
问题：在头等舱中，我的字段默认应为private. 在第二个示例中，我只能将它们设置为public. 这一切都正确还是我对 TypeScript 中默认访问修饰符的理解？
回答by Maciej Caputa
Public by default. TypeScript Documentation
默认公开。 打字稿文档
In following definition
在以下定义中
class Person implements IFieldValue{
name: string;
value: string;
constructor (name: string, value: string) {
this.name = name;
this.value = value;
}
}
Attributes <Person>.nameand <Person>.valueare public by default.
属性<Person>.name和<Person>.value默认情况下是公开的。
as they are here
因为他们在这里
class Person implements IFieldValue{
constructor(public name: string, public value: string) {
this.name = name;
this.value = value;
}
}
Beware:Here is an incorrect way of doing it, since this.nameand this.valuewill be regarded as not defined in the constructor.
注意：这是一种不正确的做法，因为this.name和this.value将被视为未在构造函数中定义。
class Person implements IFieldValue{
constructor(name: string, value: string) {
this.name = name;
this.value = value;
}
}
To make these attributes private you need to rewrite it as
要使这些属性私有，您需要将其重写为
class Person implements IFieldValue{
private name: string;
private value: string;
constructor (name: string, value: string) {
this.name = name;
this.value = value;
}
}
or equivalently
或等效地
class Person implements IFieldValue{
constructor (private name: string, private value: string) {}
}
which in my opinion is the most preferable way that avoids redundancy.
在我看来，这是避免冗余的最可取的方法。
