javascript - Method invocation pattern not working? -

i learning javascript , has called methods:

an example expect work wrote in firefox , did nothing:

var myobject = {  value: 0,  increment: function (inc) {    this.value += inc;    } };  console.writeln(myobject.value); var x = myobject.increment(2); console.writeln(x); 

what wrong?

1) use console.log instead of console.writeln

2) have return function. if don't, way value requesting value

var myobject = {     value: 0,     increment: function (inc) {         return this.value += inc;     } };