String.format()在java中格式化double

Question

我如何使用String.format(格式字符串,X)来格式化双如下？

2354548.235 - > 2,354,548.23

谢谢!

Answer 1

String.format("%1$,.2f", myDouble);

String.format 自动使用默认语言环境.

Answer 2

String.format("%4.3f" , x) ;

这意味着我们在ans中需要总共4位数,其中3位应该在十进制之后.f是double的格式说明符.x表示我们想要找到它的变量.为我工作...

Answer 3

如果要使用手动设置的符号对其进行格式化,请使用:

DecimalFormatSymbols decimalFormatSymbols = new DecimalFormatSymbols();
decimalFormatSymbols.setDecimalSeparator('.');
decimalFormatSymbols.setGroupingSeparator(',');
DecimalFormat decimalFormat = new DecimalFormat("#,##0.00", decimalFormatSymbols);
System.out.println(decimalFormat.format(1237516.2548)); //1,237,516.25

但是,基于区域设置的格式是首选.

Answer 4

从此链接提取的代码;

Double amount = new Double(345987.246);
NumberFormat numberFormatter;
String amountOut;

numberFormatter = NumberFormat.getNumberInstance(currentLocale);
amountOut = numberFormatter.format(amount);
System.out.println(amountOut + " " + 
                   currentLocale.toString());

此示例的输出显示了相同数字的格式如何随Locale而变化:

345 987,246  fr_FR
345.987,246  de_DE
345,987.246  en_US

Answer 5

public class MainClass {
   public static void main(String args[]) {
    System.out.printf("%d %(d %+d %05d\n", 3, -3, 3, 3);

    System.out.printf("Default floating-point format: %f\n", 1234567.123);
    System.out.printf("Floating-point with commas: %,f\n", 1234567.123);
    System.out.printf("Negative floating-point default: %,f\n", -1234567.123);
    System.out.printf("Negative floating-point option: %,(f\n", -1234567.123);

    System.out.printf("Line-up positive and negative values:\n");
    System.out.printf("% ,.2f\n% ,.2f\n", 1234567.123, -1234567.123);
  }
}

打印出来:

3(3)+3 00003
默认浮点格式:1234567,123000
带逗号的
浮点:1.234.567,123000 负浮点默认值:-1.234.567,123000
负浮点选项:(1.234.567, 123000)

排列正负值:1.234.567,12
-1.234.567,12