Question

I have seen the use of & in many programming language and since I love groovy a lot I tried the following code to find the use of & :

​a = 1 ;
println a & 2​

I’m getting the output as 0. When I change the values of a I get different answer’s.

So any one can say whats the use of & in programming languages like Groovy in simple english, possibly with an simple example in any language?

Thanks in advance.

Answer 1

& is usually either bitwise-and (on integer arguments) or non-short-circuiting logical and (on boolean arguments).

bitwise-and returns a series of bits (usually represented as an int type) that have only the bits in common set

18          == 10010
6           == 00110
18 & 6 == 2 == 00010

This seems to be what is happening in your Groovy code. 1 & 2 == 0 since 1 and 2 share no bits in common.

Non-short-ciruiting logical and is similar to && but

if (f() && g())   // g is only called if f returns false
if (f() &  g())   // g is called even when f returns false

In languages that allow operator overloading, libraries sometimes overloaded & to do set intersection, or element-wise bit-intersection.