如何在php版本7.41中显示json数据？

Question

我试图在下面的代码中获得$schedule的值，并希望将其转换为数组。我已经写了代码，但不能理解哪里存在问题。代码是：

class Amortization
{
    private $loan_amount;
    private $term_years;
    private $interest;
    private $terms;
    private $period;
    private $currency = "XXX";
    private $principal;
    private $balance;
    private $term_pay;

    public function __construct($data)
    {
        if ($this->validate($data)) {


            $this->loan_amount = (float)$data['loan_amount'];
            $this->term_years = (int)$data['term_years'];
            $this->interest = (float)$data['interest'];
            $this->terms = (int)$data['terms'];

            $this->terms = ($this->terms == 0) ? 1 : $this->terms;

            $this->period = $this->terms * $this->term_years;
            $this->interest = ($this->interest / 100) / $this->terms;

            $results = array(
                'inputs' => $data,
                'summary' => $this->getSummary(),
                'schedule' => $this->getSchedule(),
            );

            $this->getJSON($results);
        }
    }

    private function validate($data)
    {
        $data_format = array(
            'loan_amount' => 0,
            'term_years' => 0,
            'interest' => 0,
            'terms' => 0
        );

        $validate_data = array_diff_key($data_format, $data);

        if (empty($validate_data)) {
            return true;
        } else {
            echo "<div style='background-color:#ccc;padding:0.5em;'>";
            echo '<p style="color:red;margin:0.5em 0em;font-weight:bold;background-color:#fff;padding:0.2em;">Missing Values</p>';
            foreach ($validate_data as $key => $value) {
                echo ":: Value <b>$key</b> is missing.<br>";
            }
            echo "</div>";
            return false;
        }
    }

    private function calculate()
    {
        $deno = 1 - 1 / pow((1 + $this->interest), $this->period);

        $this->term_pay = ($this->loan_amount * $this->interest) / $deno;
        $interest = $this->loan_amount * $this->interest;

        $this->principal = $this->term_pay - $interest;
        $this->balance = $this->loan_amount - $this->principal;

        return array(
            'payment' => $this->term_pay,
            'interest' => $interest,
            'principal' => $this->principal,
            'balance' => $this->balance
        );
    }

    public function getSummary()
    {
        $this->calculate();
        $total_pay = $this->term_pay * $this->period;
        $total_interest = $total_pay - $this->loan_amount;

        return array(
            'total_pay' => $total_pay,
            'total_interest' => $total_interest,
        );
    }

    public function getSchedule()
    {
        $schedule = array();

        while ($this->balance >= 0) {
            array_push($schedule, $this->calculate());
            $this->loan_amount = $this->balance;
            $this->period--;
        }

        return $schedule;

    }

    private function getJSON($data)
    {
        header('Content-Type: application/javascript');
        echo json_encode($data);
    }
}

$data = array(
    'loan_amount' => 20000,
    'term_years' => 1,
    'interest' => 10,
    'terms' => 12
);


$amortization = new Amortization($data);
$amortization = json_decode($amortization, true);
$schedule = $amortization['schedule'];

它将错误显示为：

​

​

Answer 1

请按如下方式更改您的getJSON函数：

public function getJSON($data)
{
    return json_encode($data);
}

而你的构造函数是：

public function __construct($data)
{
    if ($this->validate($data)) {


        $this->loan_amount = (float)$data['loan_amount'];
        $this->term_years = (int)$data['term_years'];
        $this->interest = (float)$data['interest'];
        $this->terms = (int)$data['terms'];

        $this->terms = ($this->terms == 0) ? 1 : $this->terms;

        $this->period = $this->terms * $this->term_years;
        $this->interest = ($this->interest / 100) / $this->terms;

        $results = array(
            'inputs' => $data,
            'summary' => $this->getSummary(),
            'schedule' => $this->getSchedule(),
        );

        $this->result_json = $this->getJSON($results);
    }
}

public function getResultJson()
{
    return $this->result_json;
}

最后，为了得到结果：

$amortization = new Amortization($data);
$amortization = json_decode($amortization->getResultJson(), true);
$schedule = $amortization['schedule'];

但老实说，您的类需要进行大量修改。您通常不会使用构造函数来返回任何内容。这需要通过类中的某些方法来完成，比如getResultsInJSON()或其他方法，在这些方法中，您可以完成所有的数学或逻辑工作。

希望这能有所帮助