Question

Possible Duplicate:
The purpose of the comma operator in javascript (x, x1, x2, …, xn)

In Javascript (5, 2) gives 2, ('a', 'b', 'c') gives 'c' etc. (just try it out in the console).

My questions concerning that:

• Is there a reason for that “feature”?
• In which cases may it be useful?

Answer 1

You are looking at the comma operator.

The comma operator evaluates both of its operands (from left to right) and returns the value of the second operand.

You can use the comma operator when you want to include multiple
expressions in a location that requires a single expression. The most
common usage of this operator is to supply multiple parameters in a
for loop.