29_higher_order_functions.dart

// Objectives
// 1. Higher-Order Function:
// How to pass function as parameter?
// How to return a function from another function?


void main() {

	// Example One: Passing Function to Higher-Order Function
	Function addNumbers = (a, b) => print(a + b);
	someOtherFunction("Hello", addNumbers);


	// Example Two: Receiving Function from Higher-Order Function
	var myFunc = taskToPerform();
	print(myFunc(10));      // multiplyFour(10)         // number * 4       // 10 * 4       // OUTPUT: 40
}



// Example one: Accepts function as parameter
void someOtherFunction(String message, Function myFunction) {       // Higher-Order Function

	print(message);
	myFunction(2, 4);       // addNumbers(2, 4)    // print(a + b);   // print(2 + 4)       // OUTPUT: 6
}


// Example two: Returns a function
Function taskToPerform() {       // Higher-Order Function

	Function multiplyFour = (int number) => number * 4;
	return multiplyFour;
}