int32 function

int? int32(int? i)

A helper function that forces a int value into a 32-bit number.

In Dart, a int number can be a 32-bit or 64-bit number, it's dynamic to use just enough memory to store an integer number value. It's flexible but not explict, especially when these number values need to pass through a platform channel into other platforms that store number values in different and more explict types such as Java. A int number in Dart can be converted to an integer or a long number in Java according to its bit length, a 32-bit int number in Dart is converted to an integer number and the 64-bit one is going to be a long number in Java. The unclear converting in the platform channel lets to ClassCastException in Java sometimes. This function will ensures that a int value int Dart codes is 32-bit number and it will be a integer number in Java codes.

Implementation

int? int32(int? i) {
  if (i == null) {
    return i;
  } else {
    return (i & 0x7fffffff) - (i & 0x80000000);
  }
}