How to return function in Dart?

Question

As Dart docs describe it, as this being purely OOP language, Functions are also object.

This can be done in JS like this :

function functionReturningFunctionJS() {
  return function functionReturnedByFunctionJS() {
      return "This is function returned by function";
  }
}

But I could not return function from function like this n dart:

Function functionReturningFunctionDart() {
  return  functionReturnedByFunctionDart(){
    return "This is function Returned By function";
  }
} 

What is the right way to do it?

Answer 1

Please refer the below add function which returns the another function (or closure).

void main() {
  Function addTen = add(10);
  print(addTen(5)); //15
  print(add(10)(5)); //15
}

Function add(int a) {
    int innerFunction(b) {
        return a + b;
    }
    return innerFunction;
}

With anonymous function:

void main() {
  Function addTen = add(10)
  print(addTen(5)); //15
  print(add(10)(5)); //15
}

Function add(int a) {
    return (b) => a + b;
}