JAVA学习笔记03-double

package day01;

import java.math.BigDecimal;

public class DoubleDemo {
    public static void main(String[] args) {
        // double 占用 8 字节
        double a = 3.14;
        // double b = 3.14D;
        System.out.println(a);

        // 小数运算时,可能会存在误差
        double b = 3.0;
        double c = 2.9;
        System.out.println(b-c); // 0.10000000000000009
        BigDecimal b1 = BigDecimal.valueOf(3.0);
        BigDecimal c1 = BigDecimal.valueOf(2.9);
        BigDecimal test = b1.subtract(c1);
        System.out.println(test);

        double e = 6.0;
        double f = 4.9;
        System.out.println(e - f); // 1.0999999999999996

        double g = 6.0;
        double h = 1.9;
        System.out.println(g - h);// 4.1
    }
}