Java Math nextAfter() method with Example

The java.lang.Math.nextAfter() returns the floating-point number adjacent to the first argument in the direction of the second argument. If both arguments are equal then the second argument is returned.

Syntax of nextAfter() method

// datatype can be float or double. 
public static dataType nextAfter(dataType st, dataType dir) 

Parameter : 

st : starting floating-point value. 
dir :value indicating which of start's neighbors or start should be returned. 

Return:

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

Note : If one of the arguments is NaN, Output is NaN

• 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 or 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, Double.MAX_VALUE or Float.MAX_VALUE with the same sign as start is returned.
• If start is equal to Double.MAX_VALUE or 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.

Example of Java Math nextAfter() method

Example 1: 

To show the working of java.lang.Math.nextAfter() method. 

NaN
0.0
2.8E-45
3.4028235E38
1.7976931348623155E308

Example 2: