Math.Max vs inline if - what are the differences?

Question

I was working on a project today, and found myself using Math.Max in several places and inline if statements in other places. So, I was wondering if anybody knew which is "better"... or rather, what the real differences are.

For example, in the following, c1 = c2:

Random rand = new Random(); int a = rand.next(0,10000); int b = rand.next(0,10000);  int c1 = Math.Max(a, b); int c2 = a>b ? a : b; 

I'm asking specifically about C#, but I suppose the answer could be different in different languages, though I'm not sure which ones have similar concepts.

Answer 1

One of the major differences I would notice right away would be for readability sake, as far as I know for implementation/performance sake, they would be nearly equivalent.

Math.Max(a,b) is very simple to understand, regardless of previous coding knowledge.

a>b ? a : b would require the user to have some knowledge of the ternary operator, at least.

"When in doubt - go for readability"

Answer 2

I thought it would be fun to throw in some numbers into this discussion so I wrote some code to profile it. As expected they are almost identical for all practical purposes.

The code does a billion loops (yep 1 billion). Subtracting the overhead of the loop you get:

• Math.Max() took .0044 seconds to run 1 billion times
• The inline if took .0055 seconds to run 1 billion times

I subtracted the overhead which I calculated by running an empty loop 1 billion times, the overhead was 1.2 seconds.

I ran this on a laptop, 64-bit Windows 7, 1.3 Ghz Intel Core i5 (U470). The code was compiled in release mode and ran without a debugger attached.

Here's the code:

using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Diagnostics;  namespace TestMathMax {     class Program {         static int Main(string[] args) {             var num1 = 10;             var num2 = 100;             var maxValue = 0;             var LoopCount = 1000000000;             double controlTotalSeconds;             {                  var stopwatch = new Stopwatch();                 stopwatch.Start();                 for (var i = 0; i < LoopCount; i++) {                     // do nothing                 }                 stopwatch.Stop();                 controlTotalSeconds = stopwatch.Elapsed.TotalSeconds;                 Console.WriteLine("Control - Empty Loop - " + controlTotalSeconds + " seconds");             }             Console.WriteLine();             {                 var stopwatch = new Stopwatch();                 stopwatch.Start();                 for (int i = 0; i < LoopCount; i++) {                     maxValue = Math.Max(num1, num2);                 }                 stopwatch.Stop();                 Console.WriteLine("Math.Max() - " + stopwatch.Elapsed.TotalSeconds + " seconds");                 Console.WriteLine("Relative: " + (stopwatch.Elapsed.TotalSeconds - controlTotalSeconds) + " seconds");             }             Console.WriteLine();             {                 var stopwatch = new Stopwatch();                 stopwatch.Start();                 for (int i = 0; i < LoopCount; i++) {                     maxValue = num1 > num2 ? num1 : num2;                 }                 stopwatch.Stop();                 Console.WriteLine("Inline Max: " + stopwatch.Elapsed.TotalSeconds + " seconds");                 Console.WriteLine("Relative: " + (stopwatch.Elapsed.TotalSeconds - controlTotalSeconds) + " seconds");             }              Console.ReadLine();              return maxValue;         }     } } 

UPDATED Results 2/7/2015

On a Windows 8.1, Surface 3 Pro, i7 4650U 2.3Ghz Ran as a console application in release mode without the debugger attached.

• Math.Max() - 0.3194749 seconds
• Inline Max: 0.3465041 seconds