comma operator

In C and C++, the comma operator is a binary operator that evaluates its first operand and discards the result, and then evaluates the second operand and returns this value (and type).
JavaScript utilise the comma operator in the same way C/C++ does. 
In Java, the comma is a separator used to separate elements in a list in various contexts. It is not an operator and does not evaluate to the last element in the list.