jsonEncode function

1. Object? object, {
2. Object? toEncodable(
   1. Object? nonEncodable
   )?,

Converts object to a JSON string.

If value contains objects that are not directly encodable to a JSON string (a value that is not a number, boolean, string, null, list or a map with string keys), the toEncodable function is used to convert it to an object that must be directly encodable.

If toEncodable is omitted, it defaults to a function that returns the result of calling .toJson() on the unencodable object.

Shorthand for json.encode. Useful if a local variable shadows the global json constant.

Example:

const data = {'text': 'foo', 'value': 2, 'status': false, 'extra': null};
final String jsonString = jsonEncode(data);
print(jsonString); // {"text":"foo","value":2,"status":false,"extra":null}

Example of converting an otherwise unsupported object to a custom JSON format:

class CustomClass {
 final String text;
 final int value;
 CustomClass({required this.text, required this.value});
 CustomClass.fromJson(Map<String, dynamic> json)
 : text = json['text'],
 value = json['value'];
 static Map<String, dynamic> toJson(CustomClass value) =>
 {'text': value.text, 'value': value.value};
}
void main() {
 final CustomClass cc = CustomClass(text: 'Dart', value: 123);
 final jsonText = jsonEncode({'cc': cc},
 toEncodable: (Object? value) => value is CustomClass
 ? CustomClass.toJson(value)
 : throw UnsupportedError('Cannot convert to JSON: $value'));
 print(jsonText); // {"cc":{"text":"Dart","value":123}}
}

Implementation

String jsonEncode(
 Object? object, {
 Object? toEncodable(Object? nonEncodable)?,
}) => json.encode(object, toEncodable: toEncodable);