The Comma Operator

The comma operator, written as a comma (,) takes two operands. It evaluates its left operand and discards the value. It then evaluates its right operand, and returns that value as the result of the expression.

7 + 3, 6 * 2 // Gives 12
3,14         // Gives 14 (and not pi)

The comma operator is seldom necessary, except in function-like preprocessor macros, which we advise against anyway.

The commas used to separate the arguments in a call to a method, or the elements in an array, are not comma operators.