How to send total model object as a parameter of Alamofire post method in Swift3?

Since the Alamofire API is only accepting dictionaries, create a dictionary yourself!

Add a method in the model class called toJSON:

func toJSON() -> [String: Any] {
    return [
        "name": name as Any,
        "age": age as Any,
        "marks": marks as Any
    ]
}

Then call this method when calling request:

Alamofire.request(URL, 
    method:.put, 
    parameters:example.toJSON(), 
    encoding:JSONEncoding.default, 
    headers :Defines.Api.Headers )

Alternatively, use SwiftyJSON:

func toJSON() -> JSON {
    return [
        "name": name as Any,
        "age": age as Any,
        "marks": marks as Any
    ]
}

Usage:

Alamofire.request(URL, 
    method:.put, 
    parameters:example.toJSON().dictionaryObject, 
    encoding:JSONEncoding.default, 
    headers :Defines.Api.Headers )