What does a comma do in JavaScript expressions?

Question

If I use:

1.09 * 1; // returns \"1.09\"

But if I use:

1,09 * 1; // returns \"9\"

I know that 1,09 isn\'t

Answer 1

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

https://stackoverflow.com/a/3561056/5934465

It should be like this!

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

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Comma_Operator