angular-docs-cn/public/docs/js/latest/api/di_annotations/Optional-class.jade

33 lines
654 B
Plaintext

p.
<span class="location-badge">exported from <a href="/angular2/di_annotations">angular2/di_annotations</a></span>
defined in <a href="https://github.com/angular/angular/tree/master/modules/angular2/src/di/annotations.js#L75">angular2/src/di/annotations.js (line 75)</a>
:markdown
A parameter annotation that marks a dependency as optional. (Injects `null` if not found.)
```
class AComponent {
constructor(@Optional() aService:MyService) {
this.aService = aService;
}
}
```
.l-main-section
h2 Members
.l-sub-section
h3 constructor
pre.prettyprint
code.
()
:markdown