[Swift] Hit the API using Decodable / Generics

What to write in this article

-How to hit the API in Swift

Why I wrote this article

・ To check when you forget



import Foundation

// T:A structure that conforms to the Decodable protocol
internal struct Sample {
    static func fetchAPI<T:Decodable>(url url:String,completion: @escaping (T) -> Void){
        guard let urlComponents = URLComponents(string: url) else { return }
        //Set to queryItems property if you want to filter the data using a query
        //urlComponents.queryItems = [URLQueryItem(name: "name", value: "value"),]
        let task = URLSession.shared.dataTask(with: urlComponents.url!){ data,response,error in
            guard let jsonData = data else { return }
            do {
                let decodedData = try JSONDecoder().decode(T.self,from: jsonData)
            } catch {


fetchAPI(url:"https://sample.com",completion:{(data) in /*Execute processing for data here*/ })

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