Marks Dart and Flutter Blog RSS

Introduction Dart Combines Lists and Arrays In Dart, a List is an ordered Collection (sometimes called a sequence). Unlike other languages, an Array and a List have been combined together and are the same thing. A list is a number of items (objects) in an unordered structure. Additional items can be added to the list. Items can be updated or removed from the list if required. Lists may contain duplicate elements. Iterators You can use an iterator to go through the list items one by one programatically. As a developer, you will use iterators all the time. Example Note how the List in the example below (containing items...

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The mainstream Dart web development route is now writing code with Dart but compiling and running as JavaScript using webdev, which works with the build_runner utility.   Installing You will have to install the webdev package using the pub dependency manager: pub global activate webdev   This installs webdev and makes sure it is available on the command line.   Commands webdev serveRuns a development server that continuously builds a web app. webdev buildBuilds a deployable version of a web app. build_runner testRuns tests.   JavaScript Compilers When you invoke webdev, it invokes the dart2js and dartdevc JavaScript compilers in combination...

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Name Description dart Enables you to execute a .dart file within the Dart Virtual Machine. dart2js Compiles dart source code to JavaScript. dartanalyser Analyses dart source code. This is used by many of the code editors to provide error and warning highlighting. dartdevc Compiles dart source code to JavaScript. Similar to dart2js except that it supports incremental compilation, which lends itself to developers. dartdoc Generates Dart documentation from source code.  As the seminal book ‘Domain-Driven Design’ by Eric Evans states: ‘the code is the model and the model is the code’. dartfmt Formats Dart source code. This is used by...

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Dart, Dynamic, Google, Typing -

Introduction Typically, computer languages have fallen into two camps: Statically-typed languages. Dynamically-typed languages. Statically-typed Languages These languages have specific variable types and the developer compiles the code using an ‘ahead-of-time’ compiler. The compiler type checking is performed before the code is run.  This is an excellent way to develop software as the compiler performs static-analysis of the code as part of the compilation, alerting the developer when issues arise. Software typically takes longer to develop in this method, but the software developed in this manner typically works better in complex scenarios. Dynamically-typed Languages These languages don’t have specific variable types...

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Google Flutter -

Interchangeable Most of the Time You can define untyped variables by declaring them using the ‘var’ or ‘dynamic’ keywords. The ‘var’ keyword declares a variable without specifying its type, leaving the variable as a dynamic. No type is specified. The ‘dynamic’ keyword declares a variable of the type ‘dynamic’ with optional typing. It marks variable as 'not type checked'. Exception (Methods) Methods need to return a type so they will work with 'dynamic' but  wont work with 'var': void main() {   print (multiplyMethod1(2,4));   print (multiplyMethod2(2,4)); }   dynamic multiplyMethod1(int a, int b){   return a * b; }  ...

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