DART 3 (alpha release)

Srushti PatelSrushti Patel
2 min read

DART 3 is a new major release - only supports sound null safety.

DART 3 comes with two new MAJOR FEATURES - "RECORDS AND PATTERNS" , with the goal to work with structured data more productively.

Records :

“ Allows us to combine multiple datatypes to a single type”

Patterns :

“ Allows us to de-couple coupled data into its constituents”

Multiple Returns

Records are sort of like "first-class argument lists" and give you a natural way to return multiple values

  • If you don't want to access everything returned from the function, in that case, you can keep “_” at that place.

Example:

O/P:

DeStructuring:

  • Record patterns in variable declarations let you destructure a record value by accessing fields and binding the resulting values to new variables

  • List and map patterns let you likewise destructure those respective collection types

Example:

O/P:

Destructuring and assigning values to existing variables
Example:

o/p:

Json DeStructuring:

  • Can easily destructure json which is easy to use

Example:

o/p:

Example:

o/p:

Usable Switches:

  • Added guarded clauses, let you evaluate an arbitrary expression to see if that case should match

  • Also allows logical and comparison operators

Earlier:

After Dart 3.0:

  • Now, can add multiple small patterns into a single case

  • Also can add switch expressions

Control Flow in Arguments list

Earlier:

After Dart 3:

0
Subscribe to my newsletter

Read articles from Srushti Patel directly inside your inbox. Subscribe to the newsletter, and don't miss out.

Written by

Srushti Patel
Srushti Patel