How do you make a private variable in Dart?

In dart ‘ _ ‘ is used before the variable name to declare it as private . Unlike other programming languages, here private doesn’t mean it is available only to the class it is in, private means it is accessible in the file it is in and not accessible to other files.5 Tem 2013

Private variables, are variables that are visible only to the class to which they belong . Protected variables, are variables that are visible only to the class to which they belong, and any subclasses.

Privacy in Dart exists at the library, rather than the class level . That’s just not how Dart is intended to be written, partly because library-private members make it easier to define operators like ==. (Private variables of a second object couldn’t be seen for the comparison.8 Mar 2021

In Java, we can use public , protected , and private keywords to control the access scope for a property or method. However, Dart doesn’t provide that kind of keywords. Instead, you can use _ (underscore) at the start of the name to make a data member of a class becomes private .