JavaScript: parenthesis surrounding comma separated values

Question

I'm trying to get my head around the reason JS picks the last element (8):

var values = (null, 7, null, 8);
console.log(values); 
// Output: 8

console.log and alert behaves the same so I assume it's something to do with the language itself.

score 5 · Accepted Answer · answered Aug 05 '16 at 11:59

5

From the first line of the docs:

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

answered Aug 05 '16 at 11:59

Marty

score 0 · Answer 2 · answered Aug 05 '16 at 12:09

0

This one also explained beautifully link

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

answered Aug 05 '16 at 12:09

Not "both of", but "all of", and not "second", but "last". – Aug 05 '16 at 12:32

2 Answers2