Java - Math nextAfter(double x, double y) Method

Description

The Java Math nextAfter(double start, double direction) returns the floating-point number adjacent to the first argument in the direction of the second argument. If both arguments compare as equal the second argument is returned. Special cases −

  • If either argument is a NaN, then NaN is returned.

  • If both arguments are signed zeros, direction is returned unchanged (as implied by the requirement of returning the second argument if the arguments compare as equal).

  • If start is Double.MIN_VALUE and direction has a value such that the result should have a smaller magnitude, then a zero with the same sign as start is returned.

  • If start is infinite and direction has a value such that the result should have a smaller magnitude, Double.MAX_VALUE with the same sign as start is returned.

  • If startis equal to Double.MAX_VALUE and direction has a value such that the result should have a larger magnitude, an infinity with same sign as start is returned.

Declaration

Following is the declaration for java.lang.Math.nextAfter() method

public static double nextAfter(double start, double direction)

Parameters

  • start − starting floating-point value

  • direction − value indicating which of start's neighbors or start should be returned

Return Value

This method returns the floating-point number adjacent to start in the direction of direction.

Exception

NA

Getting Next Float After two Positive Double Values Example

The following example shows the usage of Math nextAfter() method for two positive values.

package com.tutorialspoint;

public class MathDemo {

   public static void main(String[] args) {

      // get two double numbers
      double x = 98759.765;
      double y = 154.28764;
   
      // print the next number for x towards y
      System.out.println("Math.nextAfter(" + x + "," + y + ")="
         + Math.nextAfter(x, y));

      // print the next number for y towards x
      System.out.println("Math.nextAfter(" + y + "," + x + ")="
         + Math.nextAfter(y, x));
   }
}

Output

Let us compile and run the above program, this will produce the following result −

Math.nextAfter(98759.765,154.28764)=98759.76499999998
Math.nextAfter(154.28764,98759.765)=154.28764000000004

Getting Next Float After a Positive and a Negative Double Value Example

The following example shows the usage of Math nextAfter() method for a positive and a negative value.

package com.tutorialspoint;

public class MathDemo {

   public static void main(String[] args) {

      // get two double numbers
      double x = -98759.765;
      double y = 154.28764;
   
      // print the next number for x towards y
      System.out.println("Math.nextAfter(" + x + "," + y + ")="
         + Math.nextAfter(x, y));

      // print the next number for y towards x
      System.out.println("Math.nextAfter(" + y + "," + x + ")="
         + Math.nextAfter(y, x));
   }
}

Output

Let us compile and run the above program, this will produce the following result −

Math.nextAfter(-98759.765,154.28764)=-98759.76499999998
Math.nextAfter(154.28764,-98759.765)=154.28763999999998

Getting Next Float After two Negative Double Values Example

The following example shows the usage of Math nextAfter() method for negative values.

package com.tutorialspoint;

public class MathDemo {

   public static void main(String[] args) {

      // get two double numbers
      double x = -98759.765;
      double y = -154.28764;
   
      // print the next number for x towards y
      System.out.println("Math.nextAfter(" + x + "," + y + ")="
         + Math.nextAfter(x, y));

      // print the next number for y towards x
      System.out.println("Math.nextAfter(" + y + "," + x + ")="
         + Math.nextAfter(y, x));
   }
}

Output

Let us compile and run the above program, this will produce the following result −

Math.nextAfter(-98759.765,-154.28764)=-98759.76499999998
Math.nextAfter(-154.28764,-98759.765)=-154.28764000000004
java_lang_math.htm
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