dart check null code example

Example 1: flutter check if null

var value = maybeSomeNumber();

if (value != null) {
  doSomething();
}

Example 2: dart null aware operator ??

print(1 ?? 3); // <-- Prints 1.
print(null ?? 12); // <-- Prints 12.

int a; // The initial value of a is null.
a ??= 3;
print(a); // <-- Prints 3.

a ??= 5;
print(a); // <-- Still prints 3.