int a = 5;
int b = 7;
int c = 19;
int d = 7;
System.Diagnostics.Stopwatch sw = new System.Diagnostics.Stopwatch();
sw.Start();
for(int i = 0; i < 1000000; i++){
if (a==c && b==d);
}
sw.Stop();
Console.WriteLine("(a==c && b==d) took " + sw.ElapsedMilliseconds + " milliseconds");
sw.Start();
for(int i = 0; i < 1000000; i++){
if (a+b == c+d);
}
sw.Stop();
Console.WriteLine("(a+b == c+d) took " + sw.ElapsedMilliseconds + " milliseconds");
Console.ReadLine();
output:
(a==c && b==d) took 3 milliseconds
(a+b == c+d) took 7 milliseconds.
Since you so impolitely stated into the reply you need a reason (which you didn't state in the question) I will let you figure it out yourself.
[EDIT]You did state it, but still you could remain more polite[/EDIT]