Objective-C几种字符串处理速度的测试数据

转载自：http://www.cocoachina.com/bbs/read.php?tid-17652-fpage-9.html

仅供参考  
测试机器 2.4 GHz Intel Core 2Duo    2GB 667 MHz DDR2   GCC 4.2

 

1. - (void)testStringSpeed:(id)sender
2. {
3.     NSAutoreleasePool *pool=[[NSAutoreleasePool alloc] init];
4.     [textField setStringValue:@""];
5.     int testi,testnum=10;
6.     float c,tm=0.0;
7.     for(testi=0;testi<testnum;testi++){
8.         NSDate *beg=[NSDate date];
9.         int i,n=10000000;
10.         for(i=0;i<n;i++){
11.             //avg=0.030204
12.             /*
13.             {
14.                 //avg=0.594266 内存基本稳定不变
15.                 NSString *t=[[NSString alloc] initWithString:@"abccc"];
16.                 [t release];
17.             }*/
18.             
19.             /*
20.             {
21.                 //avg=0.026101 内存基本稳定不变
22.                 NSString *astring = @"abcc";
23.             }*/
24.             
25.             /*
26.             {
27.                 //avg=0.278873 内存基本稳定不变
28.                 NSString *astring = [[NSString alloc] init];
29.                 astring = @"abcc";
30.                 [astring release];
31.             }*/
32.             
33.             /*
34.             {
35.                 //avg=2.737541 内存基本稳定不变
36.                 char *Cstring = "abcc";
37.                 NSString *astring = [[NSString alloc] initWithCString:Cstring];
38.                 [astring release];
39.             }*/
40.             
41.             /*
42.             {
43.                 //avg=3.619728 内存增长过快
44.                 NSString *a=[NSString stringWithString:@"abcc"];
45.             }*/
46.             
47.             /*
48.             {
49.                 //太长时间，内存增长过快
50.                 NSString *a=[NSString stringWithFormat:@"abcc%d",i];
51.             }
52.              */
53.             
54.             /*
55.             {
56.                 //avg=0.034632   内存基本稳定不变
57.                 char a[]="abcc";
58.             }*/
59.             
60.             
61.             /*
62.             {
63.                 //18.1555  内存稍有增长
64.                 NSString *a=[[NSString alloc] initWithFormat:@"abcc%d",i];
65.                 [a release];
66.             }*/
67.             
68.             /*
69.             {
70.                 //avg=2.276076   内存基本稳定不变
71.                 char a[32];
72.                 sprintf(a,"abcc%d",i);
73.             }*/
74.             
75.             /*
76.             {
77.                 //太长时间，内存增长过快
78.                 NSMutableString *a=[[NSMutableString alloc] init];
79.                 [a stringByAppendingFormat:@"abcc%d",i];
80.                 [a release];
81.             }*/
82.         }
83.         c=[[NSDate date] timeIntervalSinceDate:beg];
84.         tm+=c;
85.         [textField setStringValue:[NSString stringWithFormat:@"%@\n%d=%f",[textField stringValue],testi+1,c]];
86.     }
87.     [textField setStringValue:[NSString stringWithFormat:@"%@\navg=%f",[textField stringValue],(float)tm/testnum]];
88.     [pool release];
89. }