How to make a phone call programmatically in iOS?

I struggled lot to find this solution to make a call from iPhone using Objective C code.
Please use the below code to solve that issue.

Objective C:

NSString *phNo = @"911234567890; //91-countrycode remaining are mobile number.

NSString *phoneNumber = [NSString stringWithFormat:@"tel:%@",phNo];

[[UIApplication sharedApplication] openURL:[NSURL URLWithString:phoneNumber]];

Note: For iPad it won't work.

Swift:

let phoneNo = model.mobileNo

let newString:String = phoneNo.replacingOccurrences(of: " ", with: "")

let phoneUrl = URL(string: "telprompt:+91\(newString)")

if let callURL = phoneUrl {

     self.makeCall(callURL)

}

//makeCall function

func makeCall(_ phoneURL:URL) {

        if UIApplication.shared.canOpenURL(phoneURL) {

            UIApplication.shared.openURL(phoneURL)

        }

        else {

            let alertController = UIAlertController(title: "Warning!", message: "Not possible to make call", preferredStyle: .alert)

            let okAct = UIAlertAction(title: "OK", style: .default, handler: { (act) in

                print("OK")

            })

            alertController.addAction(okAct)

            self.present(alertController, animated: true, completion: nil)

        }

    }