double d1=123.12;
d1-=100.00;
System.out.println(d1);运行结果是
23.120000000000005如何只要23.12?再例如如果结果是432.1234000000,只要432.1234
d1-=100.00;
System.out.println(d1);运行结果是
23.120000000000005如何只要23.12?再例如如果结果是432.1234000000,只要432.1234
java.text.NumberFormat;
java.text.DecimalFormat;
d1-=100.00;
DecimalFormat nf = new DecimalFormat("0.00");
System.out.println(nf.format(d1)); nf = new DecimalFormat("0.0000");
System.out.println(nf.format(432.1234000000));The better way is: BigDecimal b= new BigDecimal(123.12D);
b.add(new BigDecimal(-100.00));
System.out.println(b.doubleValue());
b.add(new BigDecimal(-100.00));
System.out.println(b.doubleValue());
API去看看 printf()
public static void main(String args[]) {
float i;
float k;
float sum;
i = Float.parseFloat("2.00");
k = Float.parseFloat("1.10");
sum = i - k;
System.out.println("sum"+sum);
}}