不同数据类型转换

不同数据类型转换

 /****************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];
   
   
}