Flutter Null Safety

The Ultimate Guide 🎯 to Null Safety in Flutter & Dart

Null Safety is Flutter’s New Feature 🎁 released recently in Flutter 2.0. It makes Flutter & Dart more Strict & Less Prone to Errors & Bugs 🐛 . Let's Decode it !!

Coding — Photo by Clément Hélardot on Unsplash

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So, What is Null Safety?

It means that variables can only be null if we say so. For Example

For example -

int aNullableInt; is Wrong &

int? aNullableInt; is Correct.

Operators in Null Safety

• ? - This is used when you want to say that a value can be null. (Is also used as a Ternary Operator)
• ! - This is used when you know that a nullable type is not null.
• ?? - This is used to check if a value is null and if so return a default value. For eg. aNullableInt ?? 0;
• ?. - It is used for safely accessing a property or a method of an object that might be null.
• late - Used when you know that a non-nullable variable will be initialized before use later but is null for now.

Bonus Tip

If you have an App or a Package without Null Safety, just type the following command in the terminal and make it Null Safe !! -

$ dart migrate.

Assess your Null Safety Skills

Q) Which of the statements for getting John’s score is correct? (A or B ?)

Map<String, int> scores = {
    'John': 98,
    'Adam': 74,
    'Bill': 88,
};

A) int johnsScore = scores['John'];

B) int? johnsScore = scores['John'];

What do you Think ? Answer in the Comments Below ?

Want to Try Null Safety ?

Go to the Null Safe Version of DartPad here.

This was all Null Safety had to offer. I hope you learned something new. Thanks for Reading this & I will see you in the next article !!

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