[
    {
        "id": 1,
        "hadRead": false
    },
    {
        "id": 2,
        "hadRead": true
    },
    {
        "id": 3,
        "hadRead": false
    }
]

<script>

    $(function() {
        $.ajax({
            type: 'GET',
            url: '/ajax/db/data.json',
            contentType: "application/json; charset=utf-8",
            dataType: "json",
            success: function(messages){
                console.log('succsess', messages);
                $.each(messages, function(i, message) {
                    //if(message.hasRead === false){
                        $('#messages').append('<li>' + message.hasRead + '</li>');
                    //}
                });
            }
        });
    });

</script>