Operators

Operators

Most are listed here: Operator Overloading

TODO make this page a child of the User Guide
TODO the ! (not) operator; link to Groovy Truth documentation

Conditional Operators

Elvis Operator (?:)

The "Elvis operator" is a shortening of the ) which is useful for returning a 'sensible default' value if an expression resolves to false or null. A conversion of the example of the ternary operator example below would look like this:

Which translates to "if name is not null (or false) use that value, otherwise use 'Anonymous'."

Safe Navigation Operator (?.)

The Safe Navigation operator is used to avoid NullPointerException}}s. In the traditional case where you have a reference to an object you must verify that it is not null before accessing methods or properties of the object to avoid the {{NPE. To avoid this, the safe navigation operator will simply return null instead of throwing an exception, like so:

In the above example, if either user or user.address are null, streetName will be assigned null.

Ternary operator (? :)

See the section on conditional operators in the Java Tutorial. A common example:

Which means "if user.male is true, gender='male', otherwise gender='female'."

Collection-based Operators

• Spread Operator (*.)
• Range Operator (..)

Object- Related Operators

• invokeMethod and get/setProperty (.)
• Method Reference (.&)
• 'as' - "manual coercion" - asType(t) method
• Groovy == ( equals() ) behavior.
  • "is" for identity

Regular Expression Operators

• find (=~)
• match (==~)