<?php /* PHP不使用速算扣除数计算个人所得税 * @author 吴先成 * @param float $salary 含税收入金额 * @param float $deduction 保险等应当扣除的金额 默认值为0 * @param float $threshold 起征金额 默认值为3500 * @return float | false 返回值为应缴税金额 参数错误时返回false */ function getPersonalIncomeTax($salary, $deduction=0, $threshold=3500){ if(!is_numeric($salary) || !is_numeric($deduction) || !is_numeric($threshold)){  return false; } if($salary <= $threshold){  return 0; } $levels = array(1500, 4500, 9000, 35000, 55000, 80000, PHP_INT_MAX); $rates = array(0.03, 0.1, 0.2, 0.25, 0.3, 0.35, 0.45); $taxableIncome = $salary - $threshold - $deduction; $tax = 0; foreach($levels as $k => $level){  $previousLevel = isSet($levels[$k-1]) ? $levels[$k-1] : 0;  if($taxableIncome <= $level){  $tax += ($taxableIncome - $previousLevel) * $rates[$k];  break;  }  $tax += ($level-$previousLevel) * $rates[$k]; } $tax = round($tax, 2); return $tax; } /* 示例 */ echo getPersonalIncomeTax(10086.11); //运行结果：762.22?>