Objective-C字符串处理

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