Cookbook – SWIFT for Beginners – Chapter 24: Reading & Writing JSON

Free eBooks for Beginners

As a beginner in SWIFT programming, you’ll often encounter the need to read and write JSON data. JSON (JavaScript Object Notation) is a lightweight data format that is commonly used to exchange data between different systems and services. In this article, we’ll introduce you to the basics of reading and writing JSON data in SWIFT.

What is JSON?

JSON is a data format that is commonly used to exchange data between different systems and services. It is a lightweight and human-readable format that is easy to work with. JSON is based on a simple data structure that consists of key-value pairs, similar to a dictionary in SWIFT.

For example, you might have a JSON object that represents a user, with key-value pairs for the user’s name, email address, and age. In JSON, this data would be represented as follows:

{ "name": "John Doe", 
  "email": "john.doe@example.com", 
  "age": 35 
}

Reading JSON in SWIFT

To read JSON data in SWIFT, you can use the built-in JSONDecoder class. The JSONDecoder class allows you to parse JSON data into SWIFT objects. To use the JSONDecoder class, you simply need to create an instance of the class and pass the JSON data to it. The JSONDecoder class will then parse the JSON data and return a SWIFT object that you can work with.

For example, if you have the following JSON data:

{ "name": "John Doe", "email": "john.doe@example.com", "age": 35 }

You can parse this data into a SWIFT object as follows:

let jsonData = """ { "name": "John Doe", 
                     "email": "john.doe@example.com", 
                     "age": 35 } """.data(using: .utf8) 

do { 
   let user = try JSONDecoder().decode(User.self, from: jsonData) print(user) 
} 
catch { 
   print(error) 
}

Writing JSON in SWIFT

To write JSON data in SWIFT, you can use the built-in JSONEncoder class. The JSONEncoder class allows you to convert SWIFT objects into JSON data. To use the JSONEncoder class, you simply need to create an instance of the class and pass a SWIFT object to it. The JSONEncoder class will then convert the SWIFT object into JSON data that you can work with.

For example, if you have a SWIFT object that represents a user:

let user = User(name: "John Doe", 
                email: "john.doe@example.com", 
                age: 35)

You can convert this object into JSON data as follows:

do { 
   let jsonData = try JSONEncoder().encode(user) 
   let jsonString = String(data: jsonData, encoding: .utf8) 
   
   print(jsonString) 
} 

catch { 
print(error) 
}

Conclusion

Reading and writing JSON data is a common task in SWIFT programming, and the JSONDecoder and JSONEncoder classes make it easy to work with JSON data in SWIFT.

Cookbook – SWIFT for Beginners – Chapter 24: Reading & Writing JSON

Loader Loading...
EAD Logo Taking too long?

Reload Reload document
| Open Open in new tab

Download PDF [648.10 KB]

Applied Machine Learning & Data Science Projects and Coding Recipes for Beginners

A list of FREE programming examples together with eTutorials & eBooks @ SETScholars

95% Discount on “Projects & Recipes, tutorials, ebooks”

Projects and Coding Recipes, eTutorials and eBooks: The best All-in-One resources for Data Analyst, Data Scientist, Machine Learning Engineer and Software Developer

Topics included: Classification, Clustering, Regression, Forecasting, Algorithms, Data Structures, Data Analytics & Data Science, Deep Learning, Machine Learning, Programming Languages and Software Tools & Packages.
(Discount is valid for limited time only)

Disclaimer: The information and code presented within this recipe/tutorial is only for educational and coaching purposes for beginners and developers. Anyone can practice and apply the recipe/tutorial presented here, but the reader is taking full responsibility for his/her actions. The author (content curator) of this recipe (code / program) has made every effort to ensure the accuracy of the information was correct at time of publication. The author (content curator) does not assume and hereby disclaims any liability to any party for any loss, damage, or disruption caused by errors or omissions, whether such errors or omissions result from accident, negligence, or any other cause. The information presented here could also be found in public knowledge domains.