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groovy

What does that Groovy constructor like call mean?

Person person = new Person(name: "Fred", age: 42)

What does that Groovy syntax mean ? Is this a call to init a Person constructor ? What if Person class has another attribute address and occupation. Will Person(name: "Fred", age: 42) still work ?

Is there a dokumentation on this ?

Solution

  • Let's assume you have this class:

    class Person {
  String name
  int age
  String phoneNumber = "none"
  int areaCode = 0
}

    If you create a person like:

    Person person = new Person(name: "Fred", age: 42)
println person.phoneNumber // will be "none"
println person.areaCode // will be 0

    If you create a person like:

    Person person = new Person(phoneNumber: "1-222-333-444", areaCode: 10)
println person.name // will be null (not empty, as no default value exists)
println person.age // will be 0 (as int is primitive data type)

    In summary, any field that you don't specify, will have its default value.