CODEWITHSUNDEEP
javajava-8method-reference
Graeme Moss
Graeme Moss

Reputation: 8433

Is there a method reference in JDK for subtracting doubles?

Double::sum is a method reference for adding doubles, ie. (a,b) -> a+b.

Why is there not a method reference for minus in the JDK? I.e. (a,b) -> a-b?

Upvotes: 0

Views: 546

Answers (4)

Holger
Holger

Reputation: 298389

The primary purpose of methods like Double.sum is to aid use cases like reduction or Arrays.parallelPrefix Since minus is not an associative function, it is not appropriate for this use case.

Adding 3rd party library dependencies just for the sake of such a simple method, is not recommended. Keep in mind, that you always can create your own method, if you prefer named methods over lambda expressions.

E.g.

static double minus(double a, double b) {
    return a-b;
}

and using MyClass::minus is as informative as ThirdPartyClass::minus…

Upvotes: 9

Rahul Tripathi
Rahul Tripathi

Reputation: 172518

As such there is no inbuilt method which is used to subtract the doubles. However if you are using BigDecimal to store the decimals then you can try this:

BigDecimal a = new BigDecimal("10.6");
BigDecimal b = new BigDecimal("4.3");
BigDecimal result = a.subtract(b);
System.out.println(result);

else you can use the simple way of subtracting two numbers ie, a-b. Also to note that in Java, double values are IEEE floating point numbers

Upvotes: 0

David Herrero
David Herrero

Reputation: 714

Use java.math.BigDecimal

Link:http://docs.oracle.com/javase/7/docs/api/java/math/BigDecimal.html#subtract%28java.math.BigDecimal%29

Upvotes: -1

Suresh Atta
Suresh Atta

Reputation: 122008

There is no inbuilt method. But I don't think, itdo any other magic than simply doing 

double result = a-b;

It seems you are over thinking here :)

Upvotes: 2

Related Questions