Dart and Flutter Flutter – Retaining current view state
When using PageView and moving to another page and coming back to the original page, its state is clear. I just wanted t...
Dart and Flutter 
Dart and Flutter Flutter Set value from parent widget
I wanted to call a function from the parent widget to clear the current value of the child widget. To do that, we need t...
Dart and Flutter Extended widget doesn’t solve a RenderFlex overflowed error
I faced RenderFlex overflowed error while I was implementing Flutter app. I could eventually solve the problem by using ...
Dart and Flutter Flutter – How to add label to Divider widget
Flutter offers Divider widget but it is very simple one and doesn't offer label. To add label text we need to use Row wi...
JavaScript/TypeScript Testing a function specified in callback that cannot be triggered in test
Don't you have a good idea to write a test of the logic specified in a callback function? Isn't it possible to control t...
Dart and Flutter Dart – how to assign int/String values to enum
Dart supports only the simplest case on enum and its index always starts from 0. However, we often want to assign values...
Dart and Flutter Dart – Understanding Class Initialization Order
I wrote simple code to understand class initialization order. Dart offers late keyword to check null at runtime instead ...
Dart and Flutter Dart compiler doesn’t recognize if a variable is non-null value
Dart compiler doesn't recognize even though null check logic exists before using the variable. It took me a while to und...
JavaScript/TypeScript How to Restrict Possible String Arguments
I want to limit the possible string arguments. How can I do it? This article is for you. I will show 4 ways to do it. Th...
JavaScript/TypeScript Define array with multiple types in TypeScript
Union type or tuple is useful to define multiple types in an array. It shows how to define it and use cases. However, if there are multiple types in an array, it's harder to handle the difference. Using an interface is often a better choice.