{% if craft.config.devMode and (craft.session.hasFlash('notice') or craft.session.hasFlash('error')) %}

    {% set noticeFlash = craft.session.getFlash('notice')|join('|') %}
    {% set errorFlash = craft.session.getFlash('error')|join('|') %}

    Notice: [{{  noticeFlash }}]
    Error: [{{  errorFlash }}]

{% endif %}