# PHP calculator class: Perform Arithmetic operations

## PHP OOP: Exercise-16 with Solution

Write a PHP class called 'Calculator' that has a private property called 'result'. Implement methods to perform basic arithmetic operations like addition and subtraction.

**Sample Solution**:

**PHP Code :**

```
<?php
class Calculator {
private $result;
public function __construct() {
$this->result = 0;
}
public function getResult() {
return $this->result;
}
public function add($number) {
$this->result += $number;
}
public function subtract($number) {
$this->result -= $number;
}
}
$calculator = new Calculator();
$calculator->add(4);
$calculator->add(5);
$calculator->subtract(3);
$result = $calculator->getResult();
echo "Result: " . $result;
?>
```

Sample Output:

Result: 6

**Explanation:**

In the above exercise -

- The "Calculator" class has a private property $result, which is initially set to 0 in the constructor method __construct().
- The getResult() method retrieves the current value of the $result property.
- The add($number) method takes a number as a parameter and adds it to the current value of $result.
- The subtract($number) method takes a number as a parameter and subtracts it from the current value of $result.

**Flowchart: **

**PHP Code Editor:**

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