Fraction

Install

For PHP 8.4:

composer require saki/fraction: "3.*"

For PHP 8.3 and 8.2:

composer require saki/fraction: "2.*"

This library requires the BCMath extension.

Description

This is a PHP library that handles fractions using BcMath\Number. The class is final and readonly, so an immutable object.

Create a object

The constructor is:

// __construct(Number|int|string $numerator, Number|int|string $denominator = 1)

use Saki\Fraction;

$fraction = new Fraction(1, 2); // 1/2
$fraction = new Fraction('0.5', -1); // -1/2
$fraction = new Fraction('-3'); // -3/1
$fraction = new Fraction('-2', '-4'); // 1/2

You can also create objects from strings representing fractions like "1/2".

$fraction = Saki\Fraction::createFromFractionString('1/2');

Methods

The available methods are:

• add(Fraction|Number|int|string $num): Fraction
• sub(Fraction|Number|int|string $num): Fraction
• mul(Fraction|Number|int|string $num): Fraction
• div(Fraction|Number|int|string $num): Fraction
• mod(Fraction|Number|int|string $num): Fraction
• divmod(Fraction|Number|int|string $num): Fraction[]
• pow(Number|int|string $num): Fraction
• compare(Fraction|Number|int|string $num): int
• toNumber(): Number

Additionally, this class is Stringable and supports serialization.

Convert to BcMath\Number

When converting a Fraction to BcMath\Number, for example, a value like "1/10000000000" was too small and could end up as "0". Therefore, in this case, the numerator is 1 digit and the denominator is 11 digits, so the division is executed with BcMath\Number::scale extended by the 10 digits of the difference. Division of BcMath\Number automatically extends BcMath\Number::scale by up to another 10 digits from this state, so you can obtain sufficient precision.

e.g.

// Example of indivisible division

use Saki\Fraction;

$fraction = new Fraction(1, 30000);
var_dump($fraction->toNumber());

output:

object(BcMath\Number)#2 (2) {
  ["value"]=>
  string(16) "0.00003333333333"
  ["scale"]=>
  int(14)
}

Cast to string

When cast to string, it becomes a string representing a fraction, such as "-3/10".