initialize myObject by calling a function that returns an object literal

w作用域控制变量的可见范围。

JavaScript: The Good Parts

Instead of initializing myObject with an object literal, we will initialize myObject by calling a function that returns an object literal. That function defines a value variable. That variable is always available to the increment and getValue methods, but the function's scope keeps it hidden from the rest of the program

<script type="text/javascript">
    var wObject = function () {
        var value = 0;
        return {
            increment: function (inc) {
                value += typeof inc === 'number' ? inc : 1;
            },
            getValue: function () {
                return value;
            }
        }
    }();
    wf(wObject)
    function wf(w) {
        console.log(w)
    }

    wf(wObject.increment(3))
    wf(wObject.getValue())
    wf(wObject.increment(3))
    wf(wObject.getValue())

    var wObject = function () {
        var value = 0;
        return {
            increment: function (inc) {
                value += typeof inc === 'number' ? inc : 1;
                return 'www';
            },
            getValue: function () {
                return value;
            }
        }
    }();
    wf(wObject)
    function wf(w) {
        console.log(w)
    }

    wf(wObject.increment(3))
    wf(wObject.getValue())
    wf(wObject.increment(3))
    wf(wObject.getValue())
</script>