// The MIT License (MIT)

//

// Copyright (c) 2018 Robert C. Seacord

//

// Permission is hereby granted, free of charge, to any person obtaining a copy

// of this software and associated documentation files (the "Software"), to deal

// in the Software without restriction, including without limitation the rights

// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell

// copies of the Software, and to permit persons to whom the Software is

// furnished to do so, subject to the following conditions:

//

// The above copyright notice and this permission notice shall be included in all

// copies or substantial portions of the Software.

//

// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR

// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,

// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE

// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER

// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,

// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE

// SOFTWARE.

package NUM07J;

class compNaN {

@SuppressWarnings({"EqualsNaN", "IdentityBinaryExpression"})

public static void main(String[] args) {

// Do not perform a direct comparisons with NaN

double x = 0.0;

double result = Math.cos(1 / x); // returns NaN

// comparison is always false!

if (result == Double.NaN) {

System.out.println("result is NaN");

}

// Use the isNaN() method to check whether the specified value is NaN

if (Double.isNaN(result)) {

System.out.println("result is NaN");

}

// true if and only if x is NaN

if (result != result) {

System.out.println("result is NaN");

}

x = Math.cos(1 / x); // returns NaN

double y = Math.cos(1 / x); // returns NaN

// false if x or y is NaN

if ((x<y) == !(x>=y)) {

System.out.println("x and y are not NaN");

}

else {

System.out.println("result is NaN");

}

}

}