<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>