If Statements Vs Object Oreiented practices

项目
05/12/2010

When i was browsing, i found that there is a campaign called "The Anti If Campaign" https://www.antiifcampaign.com/code-recruitment.html. They are very much related to the Agile team. I read saw a claim that says the "IF Statements" are difficult to maintain and to add/delete codes inside them. They claim to use inheritance and Object Oriented best practices to enhance the code.

So i said to myself how can that impact performance? Then i decided to create this example:

Let’s take it step by step
if i have two products A & B
A comes in three flavors C, D & E.
C comes in three flavors too F, G & H.

so when you come to the bottom of it, you see that there are actually 6 products. C, D, E, F, G & H.

The If-Statement-Way

If i have a code that will simulate that scenario, it would be like this:

if( a == 1)

{

if (b == 2)

{

if (c == 3) doSomething(a, b, c);

else if (c == 4) doSomething(a, b, c);

else doSomething(a, b, c);

}

else if (b == 3) doSomething(a, b, c);

else doSomething(a, b, c);

}

else doSomething(a, b, c);

The Anti-If-Way

If you follow the people who are "Anti IF Statement", i would write the code in a different way:

public abstract class MyBaseClass

{

public int a, b, c;

public MyBaseClass() { }

public abstract void doSomething();

}

public abstract class AEqual1Class : MyBaseClass

{

public AEqual1Class() {a = 1;}

}

public abstract class BEqual2Class : AEqual1Class

{

public BEqual2Class(){b = 2;}

}

public class CEqual3Class : BEqual2Class

{

public CEqual3Class(){c = 3;}

public override void doSomething(){…}

}

public class CEqual4Class : BEqual2Class

{

public CEqual4Class(){c = 4;}

public override void doSomething(){…}

}

public class CEqualOtherClass : BEqual2Class

{

public CEqualOtherClass() {c = 100;}

public override void doSomething(){…}

}

public class BEqual3Class : AEqual1Class

{

public BEqual3Class(){b = 3;c = 100;}

public override void doSomething(){…}

}

public class BEqualOtherClass : AEqual1Class

{

public BEqualOtherClass(){b = 100;c = 100;}

public override void doSomething(){…}

}

public class AEqualOtherClass : MyBaseClass

{

public AEqualOtherClass(){a = 100;b = 100;c = 100;}

public override void doSomething(){…}

}

The Results

So i decided to compare between the two methods in all cases by calculating the execution time of each one and below are the results:

Test	in case of IF statements	*in case of NO* IF statements**
a=100, b=100, c=100	1.00619492645912 seconds	0.499456347674696 seconds
a=1, b=100, c=100	0.333323067994865 seconds	0.249895601507773 seconds
a=1, b=3, c=100	0.200379324787097 seconds	0.166854522360645 seconds
a=1, b=3, c=100	0.142798249143871 seconds	0.125212235872841 seconds
a=1, b=3, c=4	0.111325223259706 seconds	0.10132541944173 seconds
a=1, b=2, c=3	0.0910784876580769 seconds	0.0835666302589329 seconds

To be honest the results came us a surprise to me J. But I’ve learned something today.

Updated --- some people wanted to get the test project

Test Project

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

namespace AntiIfStatements

{

class Program

{

static void Main(string[] args)

{

QueryPerfCounter counter = new QueryPerfCounter();

// Calculate time per iteration in nanoseconds

double result;

counter.Start();

counter.Stop();

Console.WriteLine("in case of IF statements a=100, b=100, c=100");

counter.Start();

IIfStatements(100,100,100);

counter.Stop();

result = counter.Duration(1);