Objective-C几种字符串处理速度的测试数据

来源：互联网发布：报纸版面编辑软件编辑：程序博客网时间：2024/05/01 00:10

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

- (void)testStringSpeed:(id)sender
{
NSAutoreleasePool *pool=[[NSAutoreleasePool alloc] init];
[textField setStringValue:@""];
int testi,testnum=10;
float c,tm=0.0;
for(testi=0;testi<testnum;testi++){
NSDate *beg=[NSDate date];
int i,n=10000000;
for(i=0;i<n;i++){
//avg=0.030204
/*
{
//avg=0.594266 内存基本稳定不变
NSString *t=[[NSString alloc] initWithString:@"abccc"];
[t release];
}*/
/*
{
//avg=0.026101 内存基本稳定不变
NSString *astring = @"abcc";
}*/
/*
{
//avg=0.278873 内存基本稳定不变
NSString *astring = [[NSString alloc] init];
astring = @"abcc";
[astring release];
}*/
/*
{
//avg=2.737541 内存基本稳定不变
char *Cstring = "abcc";
NSString *astring = [[NSString alloc] initWithCString:Cstring];
[astring release];
}*/
/*
{
//avg=3.619728 内存增长过快
NSString *a=[NSString stringWithString:@"abcc"];
}*/
/*
{
//太长时间，内存增长过快
NSString *a=[NSString stringWithFormat:@"abcc%d",i];
}
*/
/*
{
//avg=0.034632 内存基本稳定不变
char a[]="abcc";
}*/
/*
{
//18.1555 内存稍有增长
NSString *a=[[NSString alloc] initWithFormat:@"abcc%d",i];
[a release];
}*/
/*
{
//avg=2.276076 内存基本稳定不变
char a[32];
sprintf(a,"abcc%d",i);
}*/
/*
{
//太长时间，内存增长过快
NSMutableString *a=[[NSMutableString alloc] init];
[a stringByAppendingFormat:@"abcc%d",i];
[a release];
}*/
}
c=[[NSDate date] timeIntervalSinceDate:beg];
tm+=c;
[textField setStringValue:[NSString stringWithFormat:@"%@/n%d=%f",[textField stringValue],testi+1,c]];
}
[textField setStringValue:[NSString stringWithFormat:@"%@/navg=%f",[textField stringValue],(float)tm/testnum]];
[pool release];
}