The “unexpected ++” error in jslint [duplicate]

Answer 1

Just add /*jslint plusplus: true */ in front of your javascript file.

Answer 2

There is something called a pre-increment: ++i and a post-increment i++ and there is a difference:

var i = 9;
alert(++i); //-> alerts 10

var j = 9;
alert(j++); //-> alerts 9
alert(j);   //-> alerts 10 now, as expected

var k = 9;
alert((k++)); //-> still alerts 9 even with extra parentheses