【JAVA】Java中BigDecimal类型的加减乘除运算

Java中BigDecimal类型的加减乘除运算

add():加法， subtract():减法:, multiply():乘法; divide():除法，

1.简单的加减乘除运算

public class test {
    public static void main(String[] args) {
        BigDecimal num1 = new BigDecimal("100");
        BigDecimal num2 = new BigDecimal("200");

        System.out.println("num1 = " + num1 + ",num2 = " + num2);
        // num1 + num2
        BigDecimal add = num1.add(num2);
        System.out.println("num1 + num2 = " + add);

        // num2 - num1
        BigDecimal subtract = num2.subtract(num1);
        System.out.println("num2 - num1 = " + subtract);

        // num1 * mun2
        BigDecimal multiply = num1.multiply(num2);
        System.out.println("num1 * num2 = " + multiply);

        // num2 /num1
        BigDecimal divide = num2.divide(num1);
        System.out.println("num2 / num1 = " + divide);
    }
}

2.除法运算
小数点后面保留2位

public class test {
    public static void main(String[] args) {
        BigDecimal num1 = new BigDecimal("5.99989");
        BigDecimal num2 = new BigDecimal("2");

        System.out.println("num1 = " + num1 + ",num2 = " + num2);

        // num2 / num1 保留2位小数
        BigDecimal divide1 = num1.divide(num2);
        System.out.println("num1 / num2 = " + divide1);
        BigDecimal divide2 = num1.divide(num2,2,BigDecimal.ROUND_HALF_UP);
        System.out.println("num1 / num2(保留2位小数，四舍五入) = " + divide2);
    }
}

ROUND_HALF_UP：四舍五入，即舍入部分大于等于0.5时进位，否则丢弃舍入部分
ROUND_HALF_DOWN:五舍六入，即舍入部分大于0.5时进位，否则丢弃舍入部分