[PHP知识库]PHP Fraction：使用分数进行运算

PHP 中没有分数类型，只有浮点数，而我们实际开发中由于浮点数精度问题，有时需要使用分数，这个 Fraction 类将会解决这个问题。
（随手写的，如有不足，欢迎指出）

代码如下：

<?php
/**
 * 名称：Fraction
 * 描述：分数类，用于定义分数、进行分数计算等
 * 作者：滑稽mc（HuajiMC@126.com）
 * Copyright ? 2021 HuajiMC. All Rights Reserved.
 */

class Fraction {
	public $nume; //分子
	public $deno; //分母
	
	private function __construct() {}
	
	/*
	创建方法1：通过整数或浮点数(不准确，不建议使用)创建分数
	$number：待转换的数值
	*/
	private function create1($number) {
		if(is_int($number)) {
			$this->create2($number,1);
		} else if(is_float($number)) {
			$this->create2($number * (10 ** 4),10 ** 4);
		}
		return $this;
	}
	
	/*
	创建方法2：通过分子分母创建分数
	$deno：分母
	$nume：分子
	*/
	private function create2($nume,$deno) {
		if(is_float($nume) || is_float($deno)) {
			$nume = $nume * (10 ** 4);
			$deno = $deno * (10 ** 4);
		}
		//化简
		$divisor = $this->max_divisor($nume,$deno);
		$this->nume = $nume / $divisor;
		$this->deno = $deno / $divisor;
		
		return $this;
	}
	
	/*
	求两个数的最大公约数
	$a：第一个数
	$b：第二个数
	*/
	public static function max_divisor($a,$b) {
		if($a % $b == 0) {
			return $b;
		} else {
			return self::max_divisor($b,$a % $b);
		}
	}
	
	/*
	将分数转换为php数据类型
	*/
	public function value() {
		return $this->nume / $this->deno;
	}
	
	public static function __callStatic($method,$args) {
		//创建分数
		if($method == 'create') {
			$name = $method . count($args);
			$obj = new self;
			return $obj->$name(...$args);
		}
	}
	
	public function __toString() {
		return $this->nume . '/' . $this->deno;
	}
	
	
	/*
	分数加法
	*/
	public static function plus(...$numbers) {
		$nume = 0;
		$deno = 1;
		foreach($numbers as $number) {
			$number = $number instanceof self ? $number : self::create($number);
			$temp = $deno;
			$nume *= $number->deno;
			$deno *= $number->deno;
			$nume = $nume + $number->nume * $temp;
		}
		return self::create($nume,$deno);
	}
	
	/*
	分数减法
	*/
	public static function subtract(...$numbers) {
		$nume = 0;
		$deno = 1;
		foreach($numbers as $number) {
			$number = $number instanceof self ? $number : self::create($number);
			$temp = $deno;
			$nume *= $number->deno;
			$deno *= $number->deno;
			$nume = $number->nume * $temp - $nume;
		}
		return self::create(-$nume,$deno);
	}
	
	/*
	分数乘法
	*/
	public static function multiply(...$numbers) {
		$nume = 1;
		$deno = 1;
		foreach($numbers as $number) {
			$number = $number instanceof self ? $number : self::create($number);
			$nume *= $number->nume;
			$deno *= $number->deno;
		}
		return self::create($nume,$deno);
	}
	
	/*
	分数除法
	*/
	public static function divide(...$numbers) {
		$result = $numbers[0];
		unset($numbers[0]);
		foreach($numbers as $number) {
			$number = $number instanceof self ? $number : self::create($number);
			$temp = $number->nume;
			$number->nume = $number->deno;
			$number->deno = $temp;
			$result = self::multiply($number,$result);
		}
		return $result;
	}
}