// This implements Interfaces which are stored in the "Code" folder referenced above
static void UseInterfaces()
{
string add = "+";
string subtract = "-";
string multiply = "*";
string divide = "/";
var numOne = 2;
var numTwo = 3;
string userChoice = add;
Dictionary <string, IMathOperator> strategies = new Dictionary <string, IMathOperator>()
{
{ "+", new MathAdd() },
{ "-", new MathSubtract() },
{ "*", new MathMultiply() },
{ "/", new MathDivide() }
};
IMathOperator selectedStrategy = strategies[userChoice];
int result = selectedStrategy.Operation(numOne, numTwo);
Console.WriteLine(result);
}
static void FancyDict(int numOne, int numTwo, string userChoice, double result)
{
// Even Better: Return functions to avoid expensive instantiating
Dictionary <string, Func <IMathOperator> > strategies = new Dictionary <string, Func <IMathOperator> >()
{
{ "+", () => new MathAdd() },
{ "-", () => new MathMinus() },
{ "*", () => new MathMultiply() },
{ "/", () => new MathDivide() }
};
IMathOperator selectedStrategy = strategies[userChoice]();
result = selectedStrategy.Operation(numOne, numTwo);
Console.WriteLine(result);
}
static void Dict(int numOne, int numTwo, string userChoice, double result)
{
// Better: Dictionary with interface
Dictionary <string, IMathOperator> strategies = new Dictionary <string, IMathOperator>()
{
{ "+", new MathAdd() },
{ "-", new MathMinus() },
{ "*", new MathMultiply() },
{ "/", new MathDivide() }
};
IMathOperator selectedStrategy = strategies[userChoice];
result = selectedStrategy.Operation(numOne, numTwo);
Console.WriteLine(result);
}