Java中的 ChoiceFormat nextDouble(double, boolean) 方法及示例

Java.text.ChoiceFormat类的nextDouble(double, boolean)方法用于在传递的布尔值为 true 时获取刚好大于传递的双精度值的双精度值，如果传递的布尔值为真，则返回比传递的双精度值稍小的双精度值传递的布尔值是假的。

句法：

public static double nextDouble(double d, boolean positive)

参数：此方法接受以下参数，如下所示

• d:-它取 double 值，要找到更大或更小的值。
• 正数：-它采用布尔值来检查返回的双精度值是否更大或更小。

返回值：如果传递的布尔值为真，则此方法返回比传递的双精度值稍大的双精度值，如果传递的布尔值为假，它将返回比传递的双精度值稍小的双精度值。

下面是说明nextDouble()方法的示例：

示例 1：

Java

// Java program to demonstrate
// nextDouble() method
 
import java.text.*;
import java.util.*;
import java.io.*;
 
public class GFG {
    public static void main(String[] argv)
    {
        // getting double value just
        // greater than the passed value
        // using nextDouble() method
        double value
            = ChoiceFormat.nextDouble(22, false);
 
        // display the result
        System.out.print("Next Double value : "
                         + value);
    }
}

输出：

Next Double value : 21.999999999999996

示例 2：

Java

// Java program to demonstrate
// nextDouble() method
 
import java.text.*;
import java.util.*;
import java.io.*;
 
public class GFG {
    public static void main(String[] argv)
    {
        // calling getValue() method
        getValue(1.23d, true);
        getValue(10d, false);
        getValue(-12d, true);
        getValue(1.2f, false);
        getValue(50, true);
    }
 
    // defining getValue() method
    public static void getValue(double doub,
                                boolean bool)
    {
 
        // getting double value just
        // greater than the passed value
        // using nextDouble() method
        double value
            = ChoiceFormat.nextDouble(doub, bool);
 
        // display the result
        if (bool)
            System.out.println("Just greater than "
                               + doub + ": "
                               + value);
        else
            System.out.println("Just lesser than "
                               + doub + ": "
                               + value);
    }
}

输出：

Just greater than 1.23: 1.2300000000000002
Just lesser than 10.0: 9.999999999999998
Just greater than -12.0: -11.999999999999998
Just lesser than 1.2000000476837158: 1.2000000476837156
Just greater than 50.0: 50.00000000000001

参考： https://docs.oracle.com/javase/9/docs/api/ Java/text/ChoiceFormat.html#nextDouble-double-boolean-