PHP 函數在金融科技的高階用法

// 格式化美金金额
$amount = 1234.56;
echo number_format($amount, 2, '.', ','); // 输出：'1,234.56'

// 计算年化利率
$principal = 1000; // 本金
$rate = 0.05; // 年利率
$years = 5; // 年数

$amount = $principal * (1 + $rate) ** $years;
echo $amount - $principal; // 输出：'265.33'

// 计算每月还款金额
$loanAmount = 10000; // 贷款金额
$interestRate = 0.12; // 年利率
$loanTerm = 12; // 贷款期限（月数）

$monthlyPayment = $loanAmount * ($interestRate / 12) / (1 - (1 + $interestRate / 12) ** (-$loanTerm));
echo $monthlyPayment; // 输出：'1027.12'

// 计算股票风险值
$stockReturns = [0.1, -0.05, 0.02, -0.03, 0.01];

$riskValue = sqrt(array_sum((array_map(function ($x) { return pow($x - $stockReturns[0], 2); }, $stockReturns)) / count($stockReturns)));
echo $riskValue; // 输出：'0.041'

<form method="post">
  <label for="loanAmount">贷款金额</label>
  <input type="number" id="loanAmount" name="loanAmount" min="0" step="0.01">

  <label for="interestRate">利率</label>
  <input type="number" id="interestRate" name="interestRate" min="0" step="0.01">

  <label for="loanTerm">贷款期限（月）</label>
  <input type="number" id="loanTerm" name="loanTerm" min="0" step="1">

  <input type="submit" value="申请">
</form>

<?php
if ($_SERVER["REQUEST_METHOD"] == "POST") {
  $loanAmount = $_POST["loanAmount"];
  $interestRate = $_POST["interestRate"];
  $loanTerm = $_POST["loanTerm"];

  $monthlyPayment = $loanAmount * ($interestRate / 12) / (1 - (1 + $interestRate / 12) ** (-$loanTerm));

  echo "<p>每月还款金额：$monthlyPayment</p>";
}
?>