保留四位小数，Java及js

classCount = "1000020.333333";

Math.round(classCount*10000)/10000;<span style="font-family: Arial, Helvetica, sans-serif;">//或者</span>

classCount.toFixed(4);

public class TestDemo {
public static void main(String[] args) {
double a=15.32743859;
double b=Math.round(a*10000)/10000.0000;//保留四位小数
System.out.println(b);
}