[Flutter/dart] Check if late variable is initialized
What want to do
There is a variable that remain unchanged once the initial value is determined.
However, it cannot be determined yet when the constructor is called.
About such variable
Define the variable with late final
Check whether it has been initialized (at some timing), and if it has not, set the initial value (if you do not check, you will get an error of assigning a value to final)
In this case, I didn't know how to check whether it was initialized.
I thought I could just check if it was null, but even if I checked for null, if I referenced an uninitialized variable, a reference error occurred.
Solution
The official opinion seems to be that such checks should not be done.
In this case, you can make it a nullable variable, set the initial value to null, and set the initial value if it is null.
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