PHP利息计算方法

r囧r小猫 2023-10-06 16:23 18阅读 0赞

## 一次性本息的利息计算 ##

/**
     * 一次性本息的利息计算
     *
     * @param int $money 本金
     * @param float $annualInterestRate 年化收益率
     * @param int $day 天数
     * @return number 利息
     */
    function interest_day($money, $annualInterestRate, $day)
    {
        
        $interestRate = $annualInterestRate / 365;
        return $money * $interestRate * $day;
    }
    
    /**
     * 一次性本息
     *
     * @param unknown $a
     */
    function aaa($cash, $rate, $month)
    {
        
        // 月利率
        $rate = $rate / 12;
        $c = $cash * $rate * $month;
        $res = [ 'total' => $cash + $c,'cash' => $cash,'rate' => $c ];
        return $c;
    }

## 利息计算 ##

/**
     * 利息计算
     *
     * @param int $money
     * @param floal $annualInterestRate
     * @param int $month
     * @param int $type 0 一次性本息 1 等额本金 2等额本息 3每月还息到期还本
     */
    function interest_count($money, $annualInterestRate, $month, $type = 0)
    {
        
        // 月利率
        $interestRate = $annualInterestRate / 12;
        $res = array ();
        if ($type == 0) {
         // 一次性本息
            $interest = $money * $interestRate * $month;
            $res [] = array ('total' => $money + $interest,'money' => $money,'interest' => $interest,'nper' => 1 );
        } elseif ($type == 1) {
         // 等额本息
                                // 每月月供额=〔贷款本金×月利率×(1＋月利率)＾还款月数〕÷〔(1＋月利率)＾还款月数-1〕
            $trate = $interestRate + 1;
            // $P = round ( ($money * $interestRate * pow ( $trate, $month )) / (pow ( $trate, $month ) - 1), 2 );
            // 每月应还本金=贷款本金×月利率×(1+月利率)^(还款月序号-1)÷〔(1+月利率)^还款月数-1〕
            $res = array ();
            for($i = 1; $i <= $month; $i ++) {
        
                $a = $money * $interestRate * pow ( $trate, $i - 1 );
                $b = pow ( $trate, $month ) - 1;
                // 每月应还利息=贷款本金×月利率×〔(1+月利率)^还款月数-(1+月利率)^(还款月序号-1)〕÷〔(1+月利率)^还款月数-1〕
                $c = $money * $interestRate * (pow ( $trate, $month ) - pow ( $trate, $i - 1 ));
                $res [$i] ['money'] = round ( $a / $b, 2 );
                $res [$i] ['interest'] = round ( $c / $b, 2 );
                $res [$i] ['nper'] = $i;
                $res [$i] ['total'] = round ( $res [$i] ['money'] + $res [$i] ['interest'], 2 );
            }
        } elseif ($type == 2) {
         // 等额本金
            $principal = $money / $month;
            $res = array ();
            for($i = 1; $i <= $month; $i ++) {
        
                // 每月应还利息=剩余本金×月利率=(贷款本金-已归还本金累计额)×月利率
                $interest = $money * $interestRate;
                $res [$i] = array ('total' => $principal + $interest,'money' => $principal,'interest' => $interest,'nper' => $i,'diminishing' => $principal * $interestRate );
                // 剩余本金
                $money = $money - $principal;
            }
        } elseif ($type == 3) {
        
            for($i = 1; $i <= $month; $i ++) {
        
                $interest = $money * $interestRate;
                if ($i == $month) {
        
                    $res [$i] = array ('total' => $money + $interest,'money' => $money,'interest' => $interest,'nper' => $i );
                } else {
        
                    $res [$i] = array ('total' => $interest,'money' => 0,'interest' => $interest,'nper' => $i );
                }
            }
        }
        return $res;
    }

## 等额本息 ##

/**
     * 等额本息
     *
     * @param int $cash 贷款总额
     * @param unknown $rate 年化收益率
     * @param int $month 贷款月数
     */
    function bbb($cash, $rate, $month)
    {
        
        $rate = $rate / 12;
        // 每月月供额=〔贷款本金×月利率×(1＋月利率)＾还款月数〕÷〔(1＋月利率)＾还款月数-1〕
        $trate = $rate + 1;
        $a = $cash * $rate * pow ( $trate, $month );
        $b = pow ( $trate, $month ) - 1;
        $P = round ( $a / $b, 2 );
        // 每月应还本金=贷款本金×月利率×(1+月利率)^(还款月序号-1)÷〔(1+月利率)^还款月数-1〕
        $res = array ();
        for($i = 1; $i <= $month; $i ++) {
        
            $a = $cash * $rate * pow ( $trate, $i - 1 );
            $b = pow ( $trate, $month ) - 1;
            // 每月应还利息=贷款本金×月利率×〔(1+月利率)^还款月数-(1+月利率)^(还款月序号-1)〕÷〔(1+月利率)^还款月数-1〕
            $c = $cash * $rate * (pow ( $trate, $month ) - pow ( $trate, $i - 1 ));
            $res [$i] ['cash'] = round ( $a / $b, 2 );
            $res [$i] ['rate'] = round ( $c / $b, 2 );
            $res [$i] ['total'] = round ( $res [$i] ['cash'] + $res [$i] ['rate'], 2 );
        }
        // 总利息=还款月数×每月月供额-贷款本金
        return $res;
    }

## 等额本金 ##

/**
     * 等额本金
     *
     * @param int $cash 贷款本金
     * @param unknown $rate 年化收益率
     * @param int $month 贷款月数
     */
    function ccc($cash, $rate, $month)
    {
        
        $rate = $rate / 12;
        // 每月应还本金=贷款本金÷还款月数 2500
        $a = $cash / $month;
        // 每月应还利息=剩余本金×月利率
        // $b = $cash * $rate;
        // 每月月供递减额 = 每月应还本金×月利率 = 贷款本金÷还款月数×月利率
        // $c = $a * $rate;
        $res = array ();
        for($i = 1; $i <= $month; $i ++) {
        
            // 每月应还利息=剩余本金×月利率=(贷款本金-已归还本金累计额)×月利率
            $d = $cash * $rate;
            // 剩余本金
            $cash = $cash - $a;
            $res [$i] = [ 'total' => $a + $d,'cash' => $a,'rate' => $d ];
        }
        // print_r ( $res );
        return $res;
    }

## 每月还息到期还本 ##

/**
     * 每月还息到期还本
     */
    function ddd($cash, $rate, $month)
    {
        
        // 月利率
        $rate = $rate / 12;
        $res = array ();
        for($i = 1; $i <= $month; $i ++) {
        
            $c = $cash * $rate;
            if ($i == $month) {
        
                $res [$i] = [ 'total' => $cash + $c,'cash' => $cash,'rate' => $c ];
            } else {
        
                $res [$i] = [ 'total' => $c,'cash' => 0,'rate' => $c ];
            }
        }
        return $res;
    }

## 按年付息到期还本 ##

/**
     * 按年付息到期还本
     *
     * @param unknown $cash
     * @param unknown $rate
     * @param unknown $month
     * @return multitype:multitype:number unknown
     */
    function eee($cash, $rate, $month)
    {
        
        $res = array ();
        for($i = 1; $i <= $month; $i ++) {
        
            $c = $cash * $rate;
            if ($i == $month) {
        
                $res [$i] = [ 'total' => $cash + $c,'cash' => $cash,'rate' => $c ];
            } else {
        
                $res [$i] = [ 'total' => $c,'cash' => 0,'rate' => $c ];
            }
        }
        return $res;
    }