angular - 为什么两个相等的对象在 Angular 2 中显示 'not equal"

Question

我从 json 文件上传数组。每 1.5 秒我检查文件是否有任何更改(目前我在一个文件上测试没有任何更改)，但是当我检查是否

    if ( this.itemsParentArray[i] !== this.itemInArray[i] )

一直显示不相等，console.log(""not equal")

我是否遗漏了代码中的某些内容？？这是:

export class HomeComponent {
itemsParentArray = [];
itemInArray = [];
myRes: Content;
showAssigned:boolean = false;

constructor(private structureRequest: StructureRequestService) {
    setInterval(() => {
        this.timerGetStructure();
    }, 1500);
}
//  using with setInterval to get new data and sets into content Array with this.updateItems(result) if it's new

timerGetStructure() {
    this.structureRequest.sendRequest().subscribe((result) => this.updateItems(result));
}
updateItems(result) {
    this.myRes =  result;
    this.itemInArray = this.myRes.content;
    for ( let i = 0; i < this.itemInArray.length; i++) {
                if ( this.itemsParentArray[i] !== this.itemInArray[i] ) {
                   // this.itemsParentArray[i] = this.itemInArray[i];
                   console.log("not equal");
                }
            }
}

//
ngOnInit() {
    //makes http request and puts result into parentArray after 3 sec.
    this.structureRequest.sendRequest().subscribe((result) => this.viewNodes(result));
}
//view items
viewNodes(result) {
    setTimeout(() => {
        this.myRes =  result;
        this.itemsParentArray = this.myRes.content;
        this.showAssigned = true;
    }, 3000);
}
}

如您所见，它从同一个文件加载数据(我不更改文件数据!!!):

this.itemsParentArray = this.myRes.content;

和(每 1.5 秒):

this.itemInArray = this.myRes.content;

Answer 1

== 尤其是 === 不检查对象是否包含具有相同值的相同属性。它只是检查它是否是相同的对象引用。

{} == {} 

或

{} === {}

也会导致 false。

另见 Typescript: Avoid comparison by reference和 How do I initialize a typescript object with a JSON object

Plunker example