If double question marks are uses it is to emphasise something in return, usually from the shock of the previous thing said . For example, if I said: ‘My dog just died’ (sad, but used for example…) Someone may reply.
Read moreWhy do some flutters have three dots?
spread operator (…) is used to provide a way to assign values to Collections , more commonly it found inside the column to render its child.
Read moreHow do you do the 3 dots flutter?
How to add 3 dot popup menu in AppBar in Flutter
Read moreWhat is dot dot in Dart?
.. is known as cascade notation . It allows you to not repeat the same target if you want to call several methods on the same object.
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