Ios NSString 转 NSNumber

   1、   NSString 转 NSNumber 

  

    NSString *str = @"120". 

    NSNumberFormatter *numberFormatter = [[NSNumberFormatter alloc] init];

    [numberFormatter setNumberStyle:NSNumberFormatterDecimalStyle];

    NSNumber *numTemp = [numberFormatter numberFromString:str];

2、 NSNumber 转NSString

    NSNumber *num = [NSNumber numberWithInt:2] ;

   NSNumberFormatter *numberFormatter = [[NSNumberFormatter alloc] init];

   NSString* str = [numberFormatter stringFromNumber:num];