Unable to convert JSON response into an array while using Angular 2

Question

Unable to convert JSON response into an array while using Angular 2

I'm currently working on converting a JSON response into an array within Angular 2. Below is the code I have implemented:

.ts file

response;
resp;
constructor(private http:Http) {
}
get()
{
this.http.get("http://localhost:3000/items")
.map(res=>res.json())
.subscribe(data=>this.response = JSON.stringify(data))

this.resp = JSON.parse(this.response);
}

component.html

{{response}}
<ul>
<li *ngFor="let k of resp">{{k}}</li>
</ul>

</div>

Even though {{response}} displays the entire JSON content, I'm struggling to iterate through the response retrieved in resp even after using JSON.parse().

Any suggestions on how to successfully convert the response into an array and access the individual properties?

json typescript angular2-http

Answer 1

Answer №1

From the code provided, it appears that you are not assigning a value to the 'resp' variable.

You seem to be storing a value in the 'response' variable and then iterating over the 'resp' variable.

To rectify this, consider using (let k of response) instead of (let k of resp).

Answer 2

From the code provided, it appears that you are not assigning a value to the 'resp' variable.

You seem to be storing a value in the 'response' variable and then iterating over the 'resp' variable.

To rectify this, consider using (let k of response) instead of (let k of resp).

Answer 3

Answer №2

To iterate over arrays in Angular, you can use ngFor. However, if your response is a JSON object, you cannot directly iterate through it using ngFor. In this case, you will need to create a custom pipe to iterate over the JSON object.

You can define a pipe like so:

@Pipe({ name: 'keys',  pure: false })
export class KeysPipe implements PipeTransform {
    transform(value: any, args: any[] = null): any {
        return Object.keys(value)
    }
}

After creating the pipe, import it into your module and add it to the declarations. Then, you can use it in your HTML like this:


{{response}}
 <ul>
    <li *ngFor="let key of resp | keys">{{key}}</li>
  </ul>

Answer 4

To iterate over arrays in Angular, you can use ngFor. However, if your response is a JSON object, you cannot directly iterate through it using ngFor. In this case, you will need to create a custom pipe to iterate over the JSON object.

You can define a pipe like so:

@Pipe({ name: 'keys',  pure: false })
export class KeysPipe implements PipeTransform {
    transform(value: any, args: any[] = null): any {
        return Object.keys(value)
    }
}

After creating the pipe, import it into your module and add it to the declarations. Then, you can use it in your HTML like this:


{{response}}
 <ul>
    <li *ngFor="let key of resp | keys">{{key}}</li>
  </ul>

Unable to convert JSON response into an array while using Angular 2

Answer №1

Answer №2

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