PHP calculator class: Perform Arithmetic operations

Last update on May 29 2025 13:07:56 (UTC/GMT +8 hours)

16. Calculator Class with Private Result

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:

For more Practice: Solve these Related Problems:

Write a PHP class Calculator with a private result property and methods for addition and subtraction that update this property.
Write a PHP script to perform a series of calculations using a Calculator object and then display the final result through a getter method.
Write a PHP function to simulate a chain of arithmetic operations using a Calculator class, ensuring proper encapsulation of the result.
Write a PHP program to extend the Calculator class to include multiplication and division while maintaining private state and error checking.

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