Cannot find a differ supporting object '[object Object]' of type 'object'. NgFor only supports binding to Iterables such as Arrays

I looked at similar questions, but none of them helped me. I am going to receive an object like the following:

[
  {
    "id": 1,
    "name": "Safa",
    "email": "neerupeeru@mail.ee",
    "purpose": "thesis",
    "programme": "Software Engineering",
    "year": 2016,
    "language": "Estonian",
    "comments": "In need of correcting a dangling participle.",
    "status": "RECEIVED"
  },
  {
    "id": 2,
    "name": "Safa",
    "email": "neerupeeru@mail.ee",
    "purpose": "thesis",
    "programme": "Software Engineering",
    "year": 2016,
    "language": "Estonian",
    "comments": "In need of correcting a dangling participle.",
    "status": "RECEIVED"
  },
  {
    "id": 3,
    "name": "Salman",
    "email": "neerupeeru@mail.ee",
    "purpose": "thesis",
    "programme": "Software Engineering",
    "year": 2016,
    "language": "Estonian",
    "comments": "In need of correcting a dangling participle.",
    "status": "RECEIVED"
  }
]

and here is my http service to receive it:

getRequest(){
        return this._http.get("http://consultationwebserver.herokuapp.com/requests").map(res => res.json());
    }

and finally, in the i called the service in this way:

requests;
    constructor(private _http:requestService){}
    ngOnInit(){
        this.requests=this._http.getRequest().subscribe(res=>this.requests=res);
    }

Unfortunately, when the page loads it complains with:

Cannot find a differ supporting object '[object Object]' of type 'object'. NgFor only supports binding to Iterables such as Arrays.

So, what is going wrong with this code?

There you don't need to use this.requests= when you are making get call(then requests will have observable subscription). You will get a response in observable success so setting requests value in success make sense(which you are already doing).

this._http.getRequest().subscribe(res=>this.requests=res);

Remove this.requests from

ngOnInit(){
  this.requests=this._http.getRequest().subscribe(res=>this.requests=res);
}

ngOnInit(){
  this._http.getRequest().subscribe(res=>this.requests=res);
}

this._http.getRequest() returns a subscription, not the response value. The response value is assigned by the callback passed to subscribe(...)

vivekinall

In your JSOn file, please make below change.

 {
    "data":
    [
      {
        "id": 1,
        "name": "Safa",
        "email": "neerupeeru@mail.ee",
        "purpose": "thesis",
        "programme": "Software Engineering",
        "year": 2016,
        "language": "Estonian",
        "comments": "In need of correcting a dangling participle.",
        "status": "RECEIVED"
      },
      {
        "id": 2,
        "name": "Safa",
        "email": "neerupeeru@mail.ee",
        "purpose": "thesis",
        "programme": "Software Engineering",
        "year": 2016,
        "language": "Estonian",
        "comments": "In need of correcting a dangling participle.",
        "status": "RECEIVED"
      },
      {
        "id": 3,
        "name": "Salman",
        "email": "neerupeeru@mail.ee",
        "purpose": "thesis",
        "programme": "Software Engineering",
        "year": 2016,
        "language": "Estonian",
        "comments": "In need of correcting a dangling participle.",
        "status": "RECEIVED"
      }
    ]
    }

And after that:

 this.http.get(url).map(res:Response) => res.json().data);

The data is actually the name of tge collection of json file. Please try the code above, I am sure it will work.

Raj Kumar

You can declare the books (on line 2) as an array:

  title: any = 'List of books are represted in the bookstore';
  books: any = []; 
  constructor(private service:  AppService){
  }

  ngOnInit(){
    this.getBookDetails();
  }

  getBookDetails() {
    this.service.getBooks().subscribe(books => {
      this.books = books.json();
      console.log(this.books);
    });
  }

I had the same error because I have mapped the HTTP response like this:

this.http.get(url).map(res => res.json);

Note how I accidentally called .json like a variable and not like a method.

Changing it to:

this.http.get(url).map(res => res.json());

did the trick.

My solution is create a Pipe for return the values array or propierties object

import { Pipe, PipeTransform } from '@angular/core';

@Pipe({
  name: 'valueArray',
})
export class ValueArrayPipe implements PipeTransform {

  // El parametro object representa, los valores de las propiedades o indice
  transform(objects : any = []) {
    return Object.values(objects);
  }
}

The template Implement

<button ion-item *ngFor="let element of element_list | valueArray" >
    {{ element.any_property }}
</button>

i have faced same problem

my initial json

{"items":

         [
           {"id":1,
            "Name":"test4"
           },
           {"id":2,
            "Name":"test1"
           }
         ]
}

i have changed my json inside []

[{"items":

         [
           {"id":1,
            "Name":"test4"
           },
           {"id":2,
            "Name":"test1"
           }
         ]
}]

i have the same problem. this is how i fixed the problem. first when the error is occurred, my array data is coming form DB like this --,

{brands: Array(5), _id: "5ae9455f7f7af749cb2d3740"}

make sure that your data is an ARRAY, not an OBJECT that carries an array. only array look like this --,

(5) [{…}, {…}, {…}, {…}, {…}]

it solved my problem.

To iterate over an object which has a json format like below

{
  "mango": { "color": "orange", "taste": "sweet" }
  "lemon": { "color": "yellow", "taste": "sour" }
}

Assign it to a variable

let rawData = { "mang":{...}, "lemon": {...} }
Create a empty array(s) for holding the values(or keys)

let dataValues = []; //For values

let dataKeys = []; //For keys
Loop over the keys and add the values(and keys) to variables

for(let key in rawData) { //Pay attention to the 'in' dataValues.push(rawData[key]); dataKeys.push(key); }
Now you have an array of keys and values which you can use in *ngFor or a for loop

for(let d of dataValues) { console.log("Data Values",d); }

<tr *ngFor='let data of dataValues'> ..... </tr>

You should use async pipe. Doc: https://angular.io/api/common/AsyncPipe

For example:

<li *ngFor="let a of authorizationTypes | async"[value]="a.id">
     {{ a.name }}
</li>

this.requests=res here you are trying to assign following response to object,

{"headers":{"normalizedNames":{},"lazyUpdate":null},"status":200,"statusText":"OK",
"url":"xyz","ok":true,"type":4,"body":[{}]}

Since, object format is different then response format you have to assign res.body part from your response to get required contents.

<ul>
<li *ngFor = "let Data of allDataFromAws  | async">
  <pre> {{ Data | json}}</pre>
</li>
</ul>

use async to convert allDataFromAws into Array Object....

In you use spring boot with Angular ; make sure that whether you create default

Rakesh Pandey

Just declare the var as an array in which you holding the data , it worked for me.

listingdata:Array<any> = [];
this.listingdata = data.results.rows;

and loop the listingdata on html page

requests = [];


this.requests[0] =this._http.getRequest().subscribe(res=>this.requests=res);

and

*ngFor="let product of requests[0]"

来源：https://stackoverflow.com/questions/39819392/cannot-find-a-differ-supporting-object-object-object-of-type-object-ngfor

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