{
    "type": "object",
    "properties": {
        "firstName": {
            "type": "string",
                         "required": true
        },
        "lastName": {
            "type": "string"
        },
        "age": {
            
            "type": "integer",
            "minimum": 0
        },
        "data":{
             "type":"object",
             "required":true,
             "properties":{
                                    
                }
        }
    }
    
}        

array
A JSON array.
boolean
A JSON boolean.
integer
A JSON number without a fraction or exponent part.
number
Any JSON number. Number includes integer.
null
The JSON null value.
object
A JSON object.
string
A JSON string.

        $json = '{"firstName":"ban", "lastName":"shan","age":1,"data":{"hobby":"coding"} }';
        $validator = new JsonSchema\Validator;
        $schema = file_get_contents("schema.json");
        $validator->check(json_decode($json), json_decode($schema));
        if ($validator->isValid()) {
            echo "The supplied JSON validates against the schema.\n";
        } else {
            echo "JSON does not validate. Violations:\n";
            foreach ($validator->getErrors() as $error) {
                echo sprintf("[%s] %s\n", $error['property'], $error['message']);
            }
        }