NSLog(@"字符串处理");
	//获得字符串长度
	NSString* str1=@"MAC OS Pro";
	NSLog(@"长度是 %d",[str1 length]);
	//两个字符串连接
	NSString* str2=@"MAC OS Pro";
	NSString* str3=@" Leopard";
	NSString* str4=[str2 stringByAppendingString:str3];
	NSLog(str4,nil);
	NSString* str5=[str2 stringByAppendingFormat:@" %d",10];
	NSLog(str5,nil); 
	//可修改字符串
	NSMutableString* string=[NSMutableString string];
	[string appendString:@"Mac"];
	[string appendString:@" OS"];
	[string appendString:@" X"];
	NSLog(string,nil); 
	//插入字符串
	NSMutableString* string1=[NSMutableString stringWithFormat:@"Mac X"];
	[string1 insertString:@"OS " atIndex:4];
	NSLog(string1,nil);
	//删除字符串
	NSMutableString* string2=[NSMutableString stringWithFormat:@"删除字符串"];
	[string2 deleteCharactersInRange:NSMakeRange(0, 2)];
	NSLog(string2,nil);
	//字符串比较
	BOOL result;
	result=[string isEqualToString:string1];
	NSLog(@"%d",result,nil);
	//比较前置串与后置串
	NSString* string3=@"Mac Pro";
	NSString* string4=@"Mac OS";
	//判断是否以Mac开头
	result=[string3 hasPrefix:@"Mac"];
	NSLog(@"%d",result,nil);
	//判断是否以OS结尾
	result=[string4 hasSuffix:@"OS"];
	NSLog(@"%d",result,nil);
	NSString* string5=@"This is Mac OS X";
	//检索字符串
	NSRange range;
	range=[string5 rangeOfString:@"Mac OS"];
	if (range.location!=NSNotFound) 
	{
		//得到字符串的位置和长度
		NSLog(@"%d,%d",range.location,range.length);
	}
	else 
	{
		NSLog(@"没有发现",nil);
	}
	//抽取部分字符串
	NSString* string6=@"This is Mac OS X";
	NSString *nstr1,*nstr2,*nstr3;
	//从开头抽取字符串
	nstr1=[string6 substringToIndex:4];
	NSLog(nstr1,nil);
	//抽取末位位置的字符串
	nstr2=[string6 substringFromIndex:8];
	NSLog(nstr2,nil);
	//抽取指定范围的字符串
	nstr3=[string6 substringWithRange:NSMakeRange(5,2)];
	NSLog(nstr3,nil);
//结果
2011-10-20 14:05:43.940 StringProcessing[1870:1307] 字符串处理
2011-10-20 14:05:43.942 StringProcessing[1870:1307] 长度是 10
2011-10-20 14:05:43.943 StringProcessing[1870:1307] MAC OS Pro Leopard
2011-10-20 14:05:43.943 StringProcessing[1870:1307] MAC OS Pro 10
2011-10-20 14:05:43.944 StringProcessing[1870:1307] Mac OS X
2011-10-20 14:05:43.945 StringProcessing[1870:1307] Mac OS X
2011-10-20 14:05:43.945 StringProcessing[1870:1307] 字符串
2011-10-20 14:05:43.946 StringProcessing[1870:1307] 1
2011-10-20 14:05:43.946 StringProcessing[1870:1307] 1
2011-10-20 14:05:43.947 StringProcessing[1870:1307] 1
2011-10-20 14:05:43.947 StringProcessing[1870:1307] 8,6
2011-10-20 14:05:43.948 StringProcessing[1870:1307] This
2011-10-20 14:05:43.948 StringProcessing[1870:1307] Mac OS X
2011-10-20 14:05:43.949 StringProcessing[1870:1307] is