How to define empty array in swagger

Question

I know how to make array of string data in swagger like this:

"photoUrls" : {
    "type":"array",
    "items":{
         "type":"string"
    }
}

It will show output like this:

"photoUrls":[
    "string"
]

How to make output like this?:

"photoUrls":[]

Answer 1

You can specify an empty array [] as an example for your array schema. This will override the default examples values generated by Swagger UI.

"photoUrls" : {
    "type":"array",
    "items":{
         "type":"string"
    },
    "example": []
}

Ron's answer is more user-friendly for your users. Consider using some real-world example values instead:

"photoUrls" : {
    "type":"array",
    "items":{
         "type":"string",
         "example": "http://example.com/images/pet.png"
    },
}

Answer 2

You don't. The idea is that

"photoUrls":[
    "string"
]

shows your users that photoUrls is an array of strings. Otherwise, they will have no way of knowing which datatype is used by the array.