Java - Math nextAfter(float x, double y) method

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Description

The Java Math nextAfter(float 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 a value equivalent to the second argument is returned. Special cases −

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

• If both arguments are signed zeros, a value equivalent to direction is returned.

• If start is Float.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, Float.MAX_VALUE with the same sign as start is returned.

• If start is equal to Float.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 float nextAfter(float 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

Example: Getting Next After for Two Positive Values

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

Output

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

Math.nextAfter(98759.766,154.28764)=98759.76

Example: Getting Next After for a Positive and Negative Value

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

Output

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

Math.nextAfter(-98759.766,154.28764)=-98759.76

Example: Getting Next After for Two Negative Values

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

Output

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

Math.nextAfter(-98759.766,-154.28764)=-98759.76