create file code about basic programming with programming language as you can

[anwar907]

just example:

// Define a function.
void printInteger(int aNumber) {
  print('The number is $aNumber.'); // Print to console.
}


// This is where the app starts executing.
void main() {
  var number = 42; // Declare and initialize a variable.
  printInteger(number); // Call a function.
}