Java中double数值保留两位小数的4种实现方式举例

import java.text.DecimalFormat;

double number = 123.456789;
DecimalFormat df = new DecimalFormat("#.##");
String formattedNumber = df.format(number);
System.out.println("Formatted Number: " + formattedNumber);

double number = 123.456789;
String formattedNumber = String.format("%.2f", number);
System.out.println("Formatted Number: " + formattedNumber);

import java.math.BigDecimal;

double number = 123.456789;
BigDecimal bd = new BigDecimal(number);
BigDecimal roundedNumber = bd.setScale(2, BigDecimal.ROUND_HALF_UP); // 设置保留两位小数并四舍五入
System.out.println("Formatted Number: " + roundedNumber);

double number = 123.456789;
double roundedNumber = Math.round(number * 100.0) / 100.0; // 保留两位小数并四舍五入
System.out.println("Formatted Number: " + roundedNumber);

import java.text.DecimalFormat;   //注意导包

double num = 520.1314;
DecimalFormat df = new DecimalFormat("0.00");
String format = df.format(num);
System.out.println(format);

import java.text.NumberFormat;

double num = 520.4444;
NumberFormat nf = NumberFormat.getNumberInstance();
nf.setMaximumFractionDigits(2); // 不足两位不补0，超过两位部分的自动舍去
//nf.setMinimumFractionDigits(2); 不足两位自动补0，超过两位的部分不舍去
System.out.println(nf.format(num));