Tips for verifying if a specific key value is present in JSON data received from the backend in an Angular application

Within my angular application, I successfully retrieved the data from the server in JSON format. Here is an example of the JSON data:

jsondata = { 
    Id: 16531914, 
    EmailId: "<a href="/cdn-cgi/l/email-protection" class="__cf_email__" data-cfemail="e9888b8aa98e84888085c78a8684">[email protected]</a>" 
}

My task is to check if 'jsondata' coming from the server contains the 'Id' field. If it does, then I need to redirect to the dashboard page; otherwise, I should navigate to the login page.

javascriptjsonangulartypescript

Answer №1

One way to achieve this is by implementing an if statement check.

if (jsonData.id) {
   return this.router.navigate([...other routes, jsonData.id]);
} else {
   this.router.navigate(['/login']);
}

Answer №2

After the JSON data has been transformed into a JavaScript object (using either JSON.parse or Angular's HttpClient internally), you have the ability to verify if a specific field exists by comparing it to null:

if (jsonData.Id !== null) {
  // execute some action
}

If you simply use if (jsonData.Id), it may not function correctly when the Id field holds a value of 0 since in JavaScript, 0 is considered falsy. By performing a loose comparison against null (!== null), you can cover cases where the field is either undefined or null, excluding 0.

Answer №3

If you want to verify the availability of an object, you can also do so

moveTo = (page) => {
  this.navigator.navigate([page]);
}

jsondata?.id ? this.moveTo(jsondata.id.toString()) : this.moveTo('login')

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