Can we use command in ternary operator (Java)?

Question

This is a working code:

String a = \"first\";
String b = \"second\";
String object;
System.out.println(object != null ? a : b);

But it isn\'t:<

Answer 1

A per the spec

It is a compile-time error for either the second or the third operand expression to be an invocation of a void method.

println is a method from the PrintStream class (which System.out is an instance of) and it has a return type of void.

Consider that the operator itself is expected to return something for use in cases such as:

 bool a = true;
 int b = a ? 1 : 2;

If you give a method returning void (i.e. nothing) as the second and/or third expression, what would the operator itself return?

Finally, Java has no lexical structure that is called a "command". System.out.println is a method invocation like any other, it just doesn't return anything.

Answer 2

The ternary operator should always return a value, whereas in case of SysOut the return type is void.