比较Java中的BigDecimal movePointRight和scaleByPowerOfTen
java.math.BigDecimal.movePointRight（intn）返回一个与该小数点等效的BigDecimal（将小数点向右移n位）。如果n为非负数，则调用仅从小数位数中减去n。
java.math.BigDecimal.scaleByPowerOfTen（intn）返回一个BigDecimal，其数值等于（this*10n）。结果的小数位数为（this.scale()-n）。
以下是显示两者的用法的示例-
示例
import java.math.BigDecimal;
public class Demo {
public static void main(String... args) {
long base = 3676;
int scale = 5;
BigDecimal d = BigDecimal.valueOf(base, scale);
System.out.println("Value = "+d);
System.out.println("\nDemonstrating moveRight()...");
BigDecimal moveRight = d.movePointRight(12);
System.out.println("Result = "+moveRight);
System.out.println("Scale = " + moveRight.scale());
System.out.println("\nDemonstrating scaleByPowerOfTen()...");
BigDecimal scaleRes = d.scaleByPowerOfTen(12);
System.out.println("Result = "+scaleRes);
System.out.println("Scale = " + scaleRes.scale());
}
}输出结果
Value = 0.03676 Demonstrating moveRight()... Result = 36760000000 Scale = 0 Demonstrating scaleByPowerOfTen()... Result = 3.676E+10 Scale = -7
在上面的程序中，首先我们研究movePointRight-
long base = 3676;
int scale = 5;
BigDecimal d = BigDecimal.valueOf(base, scale);
System.out.println("Value = "+d);
System.out.println("\nDemonstrating moveRight()...");
BigDecimal moveRight = d.movePointRight(12);
System.out.println("Result = "+moveRight);
System.out.println("Scale = " + moveRight.scale());然后我们实现了scaleByPowerOfTen-
long base = 3676;
int scale = 5;
BigDecimal d = BigDecimal.valueOf(base, scale);
System.out.println("Value = "+d);
System.out.println("\nDemonstrating scaleByPowerOfTen()...");
BigDecimal scaleRes = d.scaleByPowerOfTen(12);
System.out.println("Result = "+scaleRes);
System.out.println("Scale = " + scaleRes.scale());