Question

我正在尝试使用System.out.printf将非常大的数字舍入到2位小数。这是我正在使用的代码：

System.out.printf(" %1.2f = overpayment:$" + overpayment);

我收到此错误：

Exception in thread "main" java.util.MissingFormatArgumentException: Format specifier '%1.2f'
    at java.util.Formatter.format(Unknown Source)
    at java.io.PrintStream.format(Unknown Source)

我的印象是％f是格式说明符，％1.2f用于小数点后2位数的浮点数。我试图将4.4260494195128784E-4舍入到4.43。谢谢

由于我多付了一分钱，我认为我有错误的公式来计算它。有没有人知道如何获得多笔贷款？多付价值应为4.43。这是我的代码：

import java.util.Scanner;

公共类CreditCardPayoff {

public static void main(String[] args) {
    // TODO Auto-generated method stub
    double principle;
    double annualInterestRate;
    double monthlyPayment;
    double numerator;
    double denominator;
    double monthsToPayOff;
    double monthsToPayOffCeiled;
    double totalAmountPaid;
    double totalInterestPaid;
    double overpayment;

    Scanner keyboard = new Scanner(System.in);
    principle = keyboard.nextDouble();
    annualInterestRate = keyboard.nextDouble();
    monthlyPayment = keyboard.nextDouble();

    numerator = Math.log(monthlyPayment) - Math.log(monthlyPayment-
            (annualInterestRate / 1200.00) * principle);
    denominator = Math.log((annualInterestRate/1200.00) + 1.0);
            monthsToPayOff = numerator/denominator;

    monthsToPayOffCeiled = Math.ceil(monthsToPayOff);

    totalAmountPaid = monthsToPayOffCeiled * monthlyPayment;

    totalInterestPaid = totalAmountPaid - principle;


    overpayment = (monthsToPayOffCeiled - monthsToPayOff)/monthlyPayment;




    System.out.println("Principle:" + principle);
    System.out.println("Annual Interest Rate:" + annualInterestRate);
    System.out.println("Monthly Payment:" + monthlyPayment);

    System.out.println("Months Needed To Pay Off:" + (int)monthsToPayOffCeiled);
    System.out.println("Total Amount Paid: $" + totalAmountPaid);
    System.out.println("Total Interest Paid: $" + totalInterestPaid);
    System.out.printf("overpayment: $%1.2f ", overpayment);


}

}

我计算多付款的方法，获得monthsToPayOff和monthsToPayOffCeil（上限）之间的差额，然后除以每月付款。这让我得到了4.4260494195128784E-4。

Answer 1

这不是您使用$RunAs32Bit = { [string]$providerName ="Microsoft Base Smart Card Crypto Provider" # import CrytoAPI from advapi32.dll $signature = @" [DllImport("advapi32.dll", CharSet=CharSet.Auto, SetLastError=true)] [return : MarshalAs(UnmanagedType.Bool)] public static extern bool CryptGetProvParam( IntPtr hProv, uint dwParam, byte[] pbProvData, ref uint pdwProvDataLen, uint dwFlags); [DllImport("advapi32.dll", CharSet=CharSet.Auto, SetLastError=true)] [return : MarshalAs(UnmanagedType.Bool)] public static extern bool CryptDestroyKey( IntPtr hKey); [DllImport("advapi32.dll", CharSet=CharSet.Auto, SetLastError=true)] [return : MarshalAs(UnmanagedType.Bool)] public static extern bool CryptAcquireContext( ref IntPtr hProv, string pszContainer, string pszProvider, uint dwProvType, long dwFlags); [DllImport("advapi32.dll", CharSet=CharSet.Auto)] [return : MarshalAs(UnmanagedType.Bool)] public static extern bool CryptGetUserKey( IntPtr hProv, uint dwKeySpec, ref IntPtr phUserKey); [DllImport("advapi32.dll", CharSet=CharSet.Auto, SetLastError=true)] [return: MarshalAs(UnmanagedType.Bool)] public static extern bool CryptGetKeyParam( IntPtr hKey, uint dwParam, byte[] pbData, ref uint pdwDataLen, uint dwFlags); [DllImport("advapi32.dll", CharSet=CharSet.Auto, SetLastError=true)] [return : MarshalAs(UnmanagedType.Bool)] public static extern bool CryptReleaseContext( IntPtr hProv, uint dwFlags); "@ $CryptoAPI = Add-Type -member $signature -name advapiUtils -Namespace CryptoAPI -passthru # set some constants for CryptoAPI $AT_KEYEXCHANGE = 1 $AT_SIGNATURE = 2 $PROV_RSA_FULL = 1 $KP_CERTIFICATE = 26 $PP_ENUMCONTAINERS = 2 $PP_CONTAINER = 6 $PP_USER_CERTSTORE = 42 $CRYPT_FIRST = 1 $CRYPT_NEXT = 2 $CRYPT_VERIFYCONTEXT = 0xF0000000 [System.IntPtr]$hProvParent=0 $contextRet = $CryptoAPI::CryptAcquireContext([ref]$hprovParent,$null,$providerName,$PROV_RSA_FULL,$CRYPT_VERIFYCONTEXT) [Uint32]$pdwProvDataLen = 0 [byte[]]$pbProvData = $null $GetProvParamRet = $CryptoAPI::CryptGetProvParam($hprovParent,$PP_CONTAINER,$pbProvData,[ref]$pdwProvDataLen,0) if($pdwProvDataLen -gt 0) { $ProvData = new-Object byte[] $pdwProvDataLen $GetKeyParamRet = $CryptoAPI::CryptGetProvParam($hprovParent,$PP_CONTAINER,$ProvData,[ref]$pdwProvDataLen,0) } $enc = new-object System.Text.UTF8Encoding($null) $keyContainer = $enc.GetString($ProvData) write-host " The Default User Key Container:" $keyContainer [Uint32]$pdwProvDataLen = 0 [byte[]]$pbProvData = $null $GetProvParamRet = $CryptoAPI::CryptGetProvParam($hprovParent,$PP_USER_CERTSTORE,$pbProvData,[ref]$pdwProvDataLen,0) if($pdwProvDataLen -gt 0) { $ProvData = new-Object byte[] $pdwProvDataLen $GetKeyParamRet = $CryptoAPI::CryptGetProvParam($hprovParent,$PP_USER_CERTSTORE,$ProvData,[ref]$pdwProvDataLen,0) [uint32]$provdataInt = [System.BitConverter]::ToUInt32($provdata,0) [System.IntPtr]$hwStore = $provdataInt } $store = new-object System.Security.Cryptography.X509Certificates.X509Store($hwStore) # release smart card $ReleaseContextRet = $CryptoAPI::CryptReleaseContext($hprovParent,0) return $store } #Run the code in 32bit mode if PowerShell isn't already running in 32bit mode If($env:PROCESSOR_ARCHITECTURE -ne "x86"){ Write-Warning "Non-32bit architecture detected, collecting certificate information in separate 32bit process." $Job = Start-Job $RunAs32Bit -RunAs32 $SCStore = $Job | Wait-Job | Receive-Job }Else{ $SCStore = $RunAs32Bit.Invoke() }的方式。

printf

了解这一点，您还可以添加额外的格式：

System.out.printf("%1.2f and %d", 1.25f, 1000);

在格式字符串中，您可以指定数据类型，然后将每个数据类型作为参数传递。

Answer 2

为了使用String.format，您不会将占位符的值与格式字符串连接起来，而是将它们作为参数传递：

Drawer

Answer 3

printf为每个格式说明符提供一个参数（请参阅documentation）。在Java中，参数由逗号分隔（,）。

因此，在您的示例中，您应该使用逗号来代替连接两个字符串的+（字符串和字符串中的数字）：

System.out.printf(" %1.2f = overpayment:$", overpayment);

用java中的printf舍入数字？

3 个答案: