<script type="text/javascript">

    var jsonObj2 = { teacher: [

        { name: "jordan", sex: "m", age: "40" },

        { name: "bryant", sex: "m", age: "28" },

        { name: "McGrady", sex: "m", age: "27" }

    ]};

    var jsonObj2New = {};

    $("#btn").click(function () {

        //invoke the update

        updateData("jordan");

        var persons = jsonObj2.teacher;

        for (var i = 0; i < persons.length; i++) {

            var cur_person = persons[i];

            alert(cur_person.sex);

        }

        //invoke the delete

        deleteData("jordan");

        var persons = jsonObj2.teacher;

        for (var i = 0; i < persons.length; i++) {

            var cur_person = persons[i];

            alert(cur_person.sex);

        }

        //push

        var temp = { name: "kenny", sex: "m", age: "25" };

        jsonObj2.teacher.push(temp);

        var persons = jsonObj2.teacher;

        for (var i = 0; i < persons.length; i++) {

            var cur_person = persons[i];

            alert(cur_person.name);

        }

    });

    function updateData(name) {

        var persons = jsonObj2.teacher;

        //alert(name);

        for (var i = 0; i < persons.length; i++) {

            var cur_person = persons[i];

            if (cur_person.name == name) {

                persons[i].sex = "f";

            }

        }

    }

    function deleteData(name) {

        var persons = jsonObj2.teacher;

        //alert(name);

        for (var i = 0; i < persons.length; i++) {

            var cur_person = persons[i];

            if (cur_person.name == name) {

                jsonObj2.teacher.splice(i, 1);

            }

        }

    }

    </script>