Endgame Viable
New Collection vs. Collection.Clear
320 words
Quick, which one of the following implementations is faster to use in a time-critical section of code:
Implementation 1:
25 for( int i = ; i < iterations; i++ )
26 {
27 List<int> myList = new List<int>();
28 for( int j = ; j < 1000; j++ ) myList.Add( j );
29 }
Implementation 2:
34 List<int> myList = new List<int>();
35 for( int i = ; i < iterations; i++ )
36 {
37 myList.Clear();
38 for( int j = ; j < 1000; j++ ) myList.Add( j );
39 }
Answer: The second one, by about 33%.
1 using System;
2 using System.Collections.Generic;
3 using System.Diagnostics;
4 using System.Text;
5
6 namespace CollectionSpeedTest
7 {
8 class Program
9 {
10 static void Main( string[] args )
11 {
12 long time1 = Stopwatch.GetTimestamp();
13 Method1( 1000000 );
14 long time2 = Stopwatch.GetTimestamp();
15 Method2( 1000000 );
16 long time3 = Stopwatch.GetTimestamp();
17
18 Console.WriteLine( "Method1: {0}", time2 - time1 );
19 Console.WriteLine( "Method2: {0}", time3 - time2 );
20 Console.ReadLine();
21 }
22
23 public static void Method1( int iterations )
24 {
25 for( int i = ; i < iterations; i++ )
26 {
27 List<int> myList = new List<int>();
28 for( int j = ; j < 1000; j++ ) myList.Add( j );
29 }
30 }
31
32 public static void Method2( int iterations )
33 {
34 List<int> myList = new List<int>();
35 for( int i = ; i < iterations; i++ )
36 {
37 myList.Clear();
38 for( int j = ; j < 1000; j++ ) myList.Add( j );
39 }
40 }
41 }
42 }
Results:
Method1: 20962096146
Method2: 13987606779
Sorry, new comments are disabled on older posts. This helps reduce spam. Active commenting almost always occurs within a day or two of new posts.