It is the term used in various programming languages (not just in dart), to describe a condition where the scope of the variable is not present when the control is out of the block of code where the scope was present. Dart is a lexically scoped language, i.e. you can find the scope of the variable by the help of the braces.
Example 1: Lexical Scope of a variable.
The above code depicts, about the scope of the variable in dart function and how their scope ends outside braces.
In programming languages, a lexical closure, also called closure or function closure, is a way of implementing lexical scope name binding in a function. It is a function object that has access to variables in its lexical scope, even when the function is used outside the scope.
Note: Functions can close over variables defined in surrounding scopes. In the following example, geeksforgeeks() captures the variable addBy. Wherever the returned function goes, it remembers "add" variable.
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