How to pass zero if input text is blank? - codeigniter

Question

I am getting a bit issue with my calculation, when I pass Discount and Debit values it is doing its job, but when Values of Discount and Debit is nothing it returns a blank page. Here is my Model.. CODEIGNITER.
function createInvoice() {
$this->load->helper('date');
$date = date('Y-m-d H:i:s');
$data = array(
'Date' => $date,
'Terms_Of_Payment' => $this->input->post('termsOfPayment'),
'Sub_Total' => $this->input->post('subTotal'),
'Total' => $this->input->post('total') - $this->input->post('discount'),
'Discount' => $this->input->post('discount'),
'Debit' => $this->input->post('debit'),
'Payment_Cridet' => $this->input->post('total') - $this->input->post('debit') - $this->input->post('discount'),
'Note' => $this->input->post('note'),
'Customer_ID' => $this->input->post('customerId'),
'User_ID' => $this->session->userdata('id'));
$this->db->insert('invoice', $data);
return ($this->db->affected_rows() != 1) ? false : true;
}

Answer 1

The best way is to use the ternary operator.
$subtotal = $this->input->post('subTotal') == "" ? 0 : $this->input->post('subTotal');
And if your php version is 7.0> then use
$subtotal = $this->input->post('subTotal') ?? 0;

Answer 2

Use ternary operator at data array when assinging the value of debit and discount.Code is looks like as below:
function createInvoice() {
$this->load->helper('date');
$date = date('Y-m-d H:i:s');
$data = array(
'Date' => $date,
'Terms_Of_Payment' => $this->input->post('termsOfPayment'),
'Sub_Total' => $this->input->post('subTotal'),
'Total' => $this->input->post('total') - isset($this->input->post('discount'))?$this->input->post('discount'):0,
'Discount' => isset($this->input->post('discount'))?$this->input->post('discount'):0',
'Debit' => isset($this->input->post('debit'))?$this->input->post('debit'):0,
'Payment_Cridet' => $this->input->post('total') - isset($this->input->post('debit'))?$this->input->post('debit'):0 - isset($this->input->post('discount'))?$this->input->post('discount'):0',
'Note' => $this->input->post('note'),
'Customer_ID' => $this->input->post('customerId'),
'User_ID' => $this->session->userdata('id'));
$this->db->insert('invoice', $data);
return ($this->db->affected_rows() != 1) ? false : true;
}

Answer 3

Ternary operator logic is the process of using (condition) ? (true return value) : (false return value) statements to shorten your if/else structures.
So, you can use ternary operator login for pass zero if input text is blank.
Now, some change in your createInvoice() function like me :
$subTotal = $this->input->post('subTotal') == "" ? 0 : $this->input->post('subTotal');
$total = $this->input->post('total') == "" ? 0 : $this->input->post('total');
$discount = $this->input->post('discount') == "" ? 0 : $this->input->post('discount');
$debit = $this->input->post('debit') == "" ? 0 : $this->input->post('debit');
$data = array(
'Date' => $date,
'Terms_Of_Payment' => $this->input->post('termsOfPayment'),
'Sub_Total' => $subTotal,
'Total' => ($total - $discount),
'Discount' => $discount,
'Debit' => $debit,
'Payment_Cridet' => $total - $debit - $discount,
'Note' => $this->input->post('note'),
'Customer_ID' => $this->input->post('customerId'),
'User_ID' => $this->session->userdata('id')
);