BigDecimal类的negate()方法 (BigDecimal Class negate() method)

Syntax:

句法：

    public BigDecimal negate();
public BigDecimal negate(MathContext ma_co);

• negate() method is available in java.math package.

  negate()方法在java.math包中可用。

• negate() method is used to get a negation of this BigDecimal and its scale is non-negative.

  negate()方法用于获取此BigDecimal的取反，并且其标度为非负数。

• negate(MathContext ma_co) method is used to retrieve a negation of this BigDecimal along with rounding based on the given MathContext settings.

  negate(MathContext ma_co)方法用于检索此BigDecimal的取反以及基于给定MathContext设置的舍入。

• These methods may throw an exception at the time of the negation of an object.

  这些方法在对象取反时可能会引发异常。

  ArithmeticException: This exception may throw when the result is not accurate and set the rounding mode "UNNECESSARY".

  ArithmeticException ：当结果不正确并且将舍入模式设置为“ UNNECESSARY”时，可能会引发此异常。

• These are non-static methods and it is accessible with class objects and if we try to access these methods with the class name then we will get an error.

  这些是非静态方法，可通过类对象访问，如果尝试使用类名访问这些方法，则会收到错误消息。

Parameter(s):

参数：

• In the first case, negate(),

  在第一种情况下， negate() ，

  • It does not accept any parameter.

• In the first case, negate(MathContext ma_co),

  在第一种情况下， negate(MathContext ma_co) ，

  • MathContext ma_co – represents the context setting to use in rounding.
  • MathContext ma_co –表示要舍入的上下文设置。

Return value:

返回值：

In both the cases, the return type of the method is BigDecimal,

在这两种情况下，方法的返回类型均为BigDecimal 。

• In the first case, it returns the negation of this BigDecimal.

  在第一种情况下，它返回此BigDecimal的取反。

• In the second case, it returns the negation of this BigDecimal. with rounding if required.

  在第二种情况下，它返回此BigDecimal的取反。 如果需要，请四舍五入。

Example:

例：

// Java program to demonstrate the example 
// of negate() method of BigDecimal
import java.math.*;
public class NegateOfBD {
public static void main(String args[]) {
// Initialize two variables val1,
// val2 
String val1 = "-10.30";
int val2 = 4;
// Initialize two BigDecimal objects and
// one MathContext
BigDecimal b_dec1 = new BigDecimal(val1);
BigDecimal b_dec2 = new BigDecimal(val2);
MathContext ma_co = new MathContext(2, RoundingMode.CEILING);
System.out.println("negate(): ");
// returns the negate value of this BigDecimal
// like (-b_dec2)
BigDecimal negate = b_dec2.negate();
System.out.println("b_dec2.negate(): " + negate);
System.out.println(" ");
System.out.println("negate(MathContext): ");
// returns the negate value of this BigDecimal
// (-b_dec1) and return the result based on the given
// context settings
negate = b_dec1.negate(ma_co);
System.out.println("b_dec1.negate(ma_co): " + negate);
}
}

Output

输出量

negate(): 
b_dec2.negate(): -4negate(MathContext): 
b_dec1.negate(ma_co): 11

翻译自: https://www.includehelp.com/java/bigdecimal-negate-method-with-example.aspx