{% exit %}
This tag will prevent the rest of the template from executing, and end the request.
{% set entry = craft.entries.id(entryId).first() %}
{% if not entry %}
{% exit 404 %}
{% endif %}
# Parameters
The {% exit %} tag supports the following parameter:
# Status
If you choose to set the HTTP status code that should be included with the response, Craft will look for the appropriate error template to render. For example, {% exit 404 %} will get Craft to return the 404.twig template. If the template doesn’t exist, Craft will fall back on its own template corresponding to the status code.
{% exit %} throws an HttpException (opens new window) with the appropriate status code, so with devMode enabled a full error report and stack trace will be shown instead of an error template.