如何设置变量类型但不给它赋值?
How to set a variable type but without giving it a value?
On 和 Angular 11 个使用 Typescript 严格模式的项目我有:
export class AvatarComponent {
@Input() user: UserModel = null;
}
我收到编译错误:
Type 'null' is not assignable to type 'UserModel'.
其中 UserModel
是:
export class UserModel {
id?: number;
name?: string;
}
如何将 user
变量类型设置为 UserModel
但值为空?
我相信这样就可以了
export class AvatarComponent {
@Input() user = <UserModel>null;
}
https://stackblitz.com/edit/angular-ivy-7f6obj?file=src%2Fapp%2Fapp.component.ts
如果你想设置null
:
export class AvatarComponent {
@Input() user: UserModel | null = null;
}
如果你想设置undefined
:
export class AvatarComponent {
@Input() user: UserModel;
}
On 和 Angular 11 个使用 Typescript 严格模式的项目我有:
export class AvatarComponent {
@Input() user: UserModel = null;
}
我收到编译错误:
Type 'null' is not assignable to type 'UserModel'.
其中 UserModel
是:
export class UserModel {
id?: number;
name?: string;
}
如何将 user
变量类型设置为 UserModel
但值为空?
我相信这样就可以了
export class AvatarComponent {
@Input() user = <UserModel>null;
}
https://stackblitz.com/edit/angular-ivy-7f6obj?file=src%2Fapp%2Fapp.component.ts
如果你想设置null
:
export class AvatarComponent {
@Input() user: UserModel | null = null;
}
如果你想设置undefined
:
export class AvatarComponent {
@Input() user: UserModel;
}