Whether the format and pattern keywords can exist simultaneously under the string type

[suncpp]

code:
{ "type": "string", "pattern":"regx", "format":"regx", }
When format and pattern are both used as assertions, can they exist at the same time? Which has the highest priority?

[handrews]

@suncpp all JSON Schema keywords can be used together, and they all have the same priority. Some of these combinations make sense, and some do not (e.g. minimum is superfluous in {"type": "string", "minimum": 2} because any number will fail the type assertion), but none are forbidden.

pattern and format are often used together because depending on the draft and configuration you are using, format may or may not behave as an assertion. And even if it does, that keyword is pretty unreliable as it's not implemented consistently.

So people often use format as a semantic annotation (its default behavior in 2020-12) and use pattern to do the actual validation. e.g. {"type": "string", "format": "email", "pattern": "some-ridiculous-email-validiating-regexp"}. In that case, format serves more as machine-readable documentation.

But if you do configure things so that format has assertion behavior, then both it and pattern have equal priority in the sense that they both must pass for the schema to pass. If either fails, then the schema fails.

[suncpp]

Thank you for your reply.