不同数据类型转换

来源：互联网发布：linux 查cpu核数编辑：程序博客网时间：2024/06/06 12:34
 /****************NSString 相关********************/    //NSDictionary 转NSString    //用字符串将nsarray的元素拼接起来    NSArray *array = [NSArray arrayWithObjects:@"hello",@"world", nil];    NSString *string = [array componentsJoinedByString:@" "];    NSLog(@"string = %@",string );           //nsdata 转 nsstring    NSString *strurl = @"www.";    NSURL *url = [NSURL URLWithString:strurl];    NSData *data = [NSData dataWithContentsOfURL:url];    NSString *datastr1 = [[NSString alloc]initWithData:data encoding:NSUTF8StringEncoding];       //   NSString 转换成NSData 对象       NSData* Data = [@"testdata" dataUsingEncoding:NSUTF8StringEncoding];           //  NSData 转换成char*       NSData *data2;    const  char* a=[data2 bytes];     //nsstring zhuan char    NSString *str = @"dad";    const  char *q =[str UTF8String];    //   char* 转换成NSData对象             Byte* tempData = malloc(sizeof(Byte)*16);    NSData *content=[NSData dataWithBytes:tempData length:16];      //    NSNumber转NSString:   //    假设现有一NSNumber的变量A，要转换成NSString类型的B   //    方法如下：       NSNumberFormatter* numberFormatter = [[NSNumberFormatter alloc] init];    NSNumber *A = [[NSNumber alloc]initWithInt:5];    NSString *B;    B = [numberFormatter stringFromNumber:A];       [numberFormatter release];       //   nsstring和float 还有int之间的转换       NSString *tempA = @"123";       NSString *tempB = @"456";      //    1，字符串拼接       NSString *newString = [NSString stringWithFormat:@"%@%@",tempA,tempB];      //  2，字符转int       int intString = [newString intValue];      //   3，int转字符       NSString *stringInt = [NSString stringWithFormat:@"%d",intString];      //4，字符转float       float floatString = [newString floatValue];      //    5，万能公式其他转字符       NSString *stringFloat = [NSString stringWithFormat:@"%f",floatString];//      }   //nsdictionary 相关//字典nsdictionary 转成json- (NSString *)dictionaryToJason:(NSDictionary *)dic{    NSData *jsondata = [NSJSONSerialization dataWithJSONObject:dic options:NSJSONWritingPrettyPrinted error:nil];    return [[NSString alloc]initWithData:jsondata encoding:NSUTF8StringEncoding];      }
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