<script type="text/javascript">
    //<![CDATA[

            function bar(a, b) {
                alert(a);
                alert(b);
            }

            function foo(x, y) {
                x = 'never-online';
                y = 'BlueDestiny';
                bar.call(null, x, y);
            }

            function foo2(x, y) {
                var x = 'never-online2';
                var y = 'BluDestiny2';
                bar.call(null, x, y);
            }

            foo(1, 2); //目测foo函数里执行bar函数的打印结果 a=?, b=?
            foo2(1, 2); //目测foo2函数里执行bar函数的打印结果 a=?, b=?

    //]]>
    </script>

    <script type="text/javascript">
    //<![CDATA[

            function bar(a, b) {
                alert(a);
                alert(b);
            }

            function showSomething(a) {
                alert(a);
            }

            function foo(x, y) {
                x = 'never-online';
                y = 'BlueDestiny';
                bar.apply(null, arguments);
            }

            function foo2(x, y) {
                showSomething(x); //输出x=?
                var x = 'never-online2'+x;
                var y = 'BluDestiny2'+y;
                bar.apply(null, arguments);
            }

            foo(1, 2); //目测foo函数里执行bar函数的打印结果 a=?, b=?
            foo2(1, 2); //目测foo2函数里执行bar函数的打印结果 a=?, b=?

    //]]>
    </script>

<script type="text/javascript">
    //<![CDATA[

            function bar(a, b) {
                alert(a);
                alert(b);
            }

            function foo(x, y) {
                x = 'never-online';
                y = 'BlueDestiny';
                bar.apply(null, arguments);
            }

            function foo2(x, y) {
                var x = 'never-online2';
                var y = 'BluDestiny2';
                bar.apply(null, arguments);
            }

            foo(); //目测foo函数里执行bar函数的打印结果 a=?, b=?
            foo2(1, 2); //目测foo2函数里执行bar函数的打印结果 a=?, b=?

    //]]>
    </script>

<script type="text/javascript">
    //<![CDATA[

            function bar(a, b) {
                alert(a);
                alert(b);
            }

            function foo(x, y) {
                x = 'never-online';
                y = 'BlueDestiny';
                bar.apply(null, arguments);
            }

            function foo2(x, y) {
                var x = 'never-online2';
                var y = 'BluDestiny2';
                bar.apply(null, arguments);
            }

            foo(1); //目测foo函数里执行bar函数的打印结果 a=?, b=?
            foo2(1, 2); //目测foo2函数里执行bar函数的打印结果 a=?, b=?

    //]]>
    </script>