TypeError: Cannot read property 'result' of undefined at SafeSubscriber._next

Do you know how to fix this?:frowning:

loadCustomer() {
    return new Promise(resolve => {
      const body = {
        aksi: 'getdata',
        limit: this.limit,
        start: this.start,
      };

      this.postPrvdr.postData(body, 'proses-api.php').subscribe(data => {
        for (const customer of data.result) {
          console.log(customer);
          this.customers.push(customer);
        }
        resolve(true);
      });
    });
  }

from php file

  	$data = array();
  	$query = mysqli_query($mysqli, "SELECT * FROM hawkers  ORDER BY customerid DESC LIMIT $postjson[start],$postjson[limit]");

  	while($row = mysqli_fetch_array($query)){

  		$data[] = array(
  			'customerid' => $row['customerid'],
  			'namecustomer' => $row['namecustomer'],
  			'desccustomer' => $row['desccustomer'],
  			'created_at' => $row['created_at'],

  		);
  	}

  	if($query) $result = json_encode(array('success'=>true, 'result'=>$data));
  	else $result = json_encode(array('success'=>false));

  	echo $result;

  }
type or paste code here