OOP_Adv_Calc

On portfolio page, oop_adv_calc.php, must we also use mySql? The tutorial letter says that we must use the knowledge gained from step 7.

Tutorial Letter 102

Step 7: Create a database on the server, and add three tables. The 1st table is named model, the 2nd table is named colour, and the 3rd table is named availability.

Another problem that I have is that when I use the class with the constructor, my calculator does not work and when I remove the function ___construct it works. Is it fine if I use the class without the constructor?

Example code:

Language: PHP
<?php
// Defines the class Calculator
class Calculator {
	// variables for value 1 input and value 2 input
	private $val1, $val2;
		// public function to add value1 and value2
        public function add($val1,$val2){
            $result = $val1 + $val2;
			// message to display after calculation
            echo("The sum of $val1 and $val2 is $result<br><br>");
            echo("$val1 + $val2 = $result");
        }

The knowledge gained i.e. using a form

You can leave the constructor out

I'm a bit confused by the following statement:

the form data is sent to the same page.

Must the data be sent back to the input boxes or just displayed somewhere on the page?

Hi Coder.

Just display the output somewhere on the same page. I.E. (4+4 = 8)

this is how I did it:




Advanced calculator
First Number

Second Number

add subtract multiply divide


The result of your calculation is: 48

DF