自动化出算术题-拿给儿子练速算吧 o(∩_∩)o

自定义范围，自定义运算符，自定义运算次数。太牛逼了

/**
 * Description of QuestionEngine
 * 出题引擎一枚
 *
 * @author lyc
 * @copyright (c) 2013, Unary Inc.
 */
class QuestionEngine {

    /**
     * 出题范围
     * @var string $scope
     */
    public $scope = array(1, 100);

    /**
     * 包含的运算符，含有多个则混合出题
     * @var string $operators
     */
    public $operators = '+-';

    /**
     * 运算次数
     * @var int
     */
    public $optTimes = 1;

    public function generate() {
        //按运算次数产生一组数值
        start:
        for ($index = 0; $index optTimes + 1; $index++) {
            $elements[] = $this->randomValue();
        }
        $operatorType = strlen($this->operators); //有几个运算符供选择
        //开始组装算式
        $question = '';
        for ($index = 0; $index             $question.=' ' . $elements[$index] . ' '; //放一个数字进来
            if ($index                 $question.=substr($this->operators, mt_rand(0, $operatorType - 1), 1);
        }

        eval('$anwser = ' . $question . ';');
        if ($anwser             $elements = array();
            goto start;     //需PHP5.3的支持
        }

        echo "$question= " . $anwser;
    }

    /**
     * 产生一个范围内的随机值
     *
     * @return int
     */
    protected function randomValue() {
        return mt_rand($this->scope[0], $this->scope[1]);
    }

}

include 'QuestionEngine.class.php';
$hello = new QuestionEngine();
$hello->generate();
?>

结果：26 + 85 = 111