typescript Angular2 检查对象是否在 *ngIf 中具有 peoperty
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/43136846/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
提示：将鼠标放在中文语句上可以显示对应的英文。显示中英文
时间：2020-10-21 04:24:22 来源:igfitidea点击:
Angular2 check if object has peoperty inside *ngIf
提问by Pratap A.K
export interface Element {
name: string;
}
export class Room implements Element {
name: string;
type:string
}
export class Hall implements Element {
name: string;
}
and my varibale type is like below
我的变量类型如下
selectedElement: Element;
now in html how can I check if the object is having property 'type' or not?
现在在 html 中如何检查对象是否具有属性“类型”？
<div *ngIf="selectedElement?.type">
my div
</div>
回答by Sniper
You can do it simply in the html:
你可以简单地在 html 中做到这一点：
<div *ngIf="selectedElement.hasOwnProperty('type')">
my div
</div>
or
或者
<div *ngIf="selectedElement.hasOwnProperty('type');then
showMyDiv">...</div>
<ng-template #showMyDiv>
my div
</ng-template>
回答by Günter Z?chbauer
I guess this should do what you want:
我想这应该做你想做的：
*ngIf="hasProp(selectedElement, 'type')"
hasProp(o, name) {
return o.hasOwnProperty(name);
}
回答by Bougarfaoui El houcine
in addition to what Günter Z?chbauersaid:
除了Günter Z?chbauer所说的：
*ngIf="selectedElement && selectedElement['type']"
