<?php

/**

 * BC Math 函数示例

 * Class BCCalculate

 */

class BCCalculate

{

    private $leftNumber;// 左操作数

    private $rightNumber;// 右操作数

    public function __construct($leftNumber, $rightNumber)

    {

        $this->leftNumber = $leftNumber;

        $this->rightNumber = $rightNumber;

        $this->setScale();

    }

    /**

     * 设置数字

     * @param $name

     * @param $value

     * @return null

     */

    public function __set($name, $value)

    {

        if (!isset($this->$name)) {

            return null;

        }

        $this->$name = $value;

    }

    /**

     * 获取数字

     * @param $name

     * @return null

     */

    public function __get($name)

    {

        if (isset($this->$name)) {

            return $this->$name;

        } else {

            return null;

        }

    }

    /**

     * 执行方法

     * @param $functionName

     * @param string $arguments

     * @return null

     */

    public function __call($functionName, $arguments)

    {

        if (!method_exists($this, $functionName)) {

            return null;

        }

        // 设置小数点位数需要参数，其他不需要

        if (isset($arguments[0])) {

            return $this->$functionName($arguments[0]);

        }

        return $this->$functionName();

    }

    /**

     * 设置所有bc数学函数的默认小数点保留位数

     * http://php.net/manual/zh/function.bcscale.php

     * @param int $scale

     */

    private function setScale($scale = 2)

    {

        bcscale($scale);

    }

    /**

     * 2个任意精度数字的加法计算

     * http://php.net/manual/zh/function.bcadd.php

     * @return string

     */

    private function add()

    {

        return bcadd($this->leftNumber, $this->rightNumber);

    }

    /**

     * 2个任意精度数字的减法

     * http://php.net/manual/zh/function.bcsub.php

     * @return string

     */

    private function sub()

    {

        return bcsub($this->leftNumber, $this->rightNumber);

    }

    /**

     * 2个任意精度数字乘法计算

     * http://php.net/manual/zh/function.bcmul.php

     * @return string

     */

    private function mul()

    {

        return bcmul($this->leftNumber, $this->rightNumber);

    }

    /**

     * 2个任意精度的数字除法计算

     * http://php.net/manual/zh/function.bcp.php

     * @return string

     */

    private function p()

    {

        return bcp($this->leftNumber, $this->rightNumber);

    }

    /**

     * 比较两个任意精度的数字

     * 相等返回 0 ；左大于右返回 1 ；右大于左返回 -1

     * http://php.net/manual/zh/function.bccomp.php

     * @return int

     */

    private function comp()

    {

        return bccomp($this->leftNumber, $this->rightNumber);

    }

    /**

     * 对一个任意精度数字取模

     * http://php.net/manual/zh/function.bcmod.php

     * @return string

     */

    private function mod()

    {

        return bcmod($this->leftNumber, $this->rightNumber);

    }

    /**

     * 任意精度数字的乘方

     * http://php.net/manual/zh/function.bcpow.php

     * @return string

     */

    private function pow()

    {

        return bcpow($this->leftNumber, $this->rightNumber);

    }

    /**

     * 任意精度数字的二次方根

     * http://php.net/manual/zh/function.bcsqrt.php

     * @return string

     */

    private function sqrt()

    {

        return bcsqrt($this->leftNumber);

    }

}

$bc = new BCCalculate(3.45, 5.61);

var_dump($bc->leftNumber);// 获取数字 float(3.45)

echo '<br />';

$bc->leftNumber = 24.08;

var_dump($bc->leftNumber);// 修改数字 float(24.08)

echo '<br />';

var_dump($bc->add());// 注意返回值是字符串 string(5) "29.69"

echo '<br />';

$bc->setScale(3);// 修改小数点后位数

var_dump($bc->sub());// string(6) "18.470"

echo '<br />';

var_dump($bc->mul());// string(7) "135.088"

echo '<br />';

var_dump($bc->p());// string(5) "4.292"

echo '<br />';

var_dump($bc->comp());// int(1)

echo '<br />';

$bc->leftNumber = 10;

$bc->rightNumber = 4;

var_dump($bc->mod());// string(1) "2"

echo '<br />';

var_dump($bc->pow());// string(5) "10000"

echo '<br />';

$bc->leftNumber = 16;

var_dump($bc->sqrt());// string(5) "4.000"

echo '<br />';