Conditional JSON parsing in Dart 3¶

How do you parse JSON objects that may contain different properties depending on a given field?

An example of this would be when you have a `Shape`` class with two subclasses:

• a Square (with a “side” property)
• a Circle (with a “radius” property)

Let’s take a look. 👇

To begin, add a factory constructor to the base class (this will contain the parsing code).

Then, you can write some conditional logic as a chain of if/else statements.

And depending on the type, you can return Square or `Circle`` instances as needed.

As an alternative, you can use switch expressions.

This way, you can leverage pattern matching to restructure the properties you need (side, radius) and return the corresponding objects. 👌