objective-c: how to assign string to NSMutableData?

Question

I am to send data to digital meter for which I want data in NSMutableData form. I am trying to assign it data but getting errors.

NSMutableData *body = [[NSMuta         


        

Answer 1

NSString *str = @"ABC";    
NSMutableData* body = (NSMutableData *)[str dataUsingEncoding:NSUTF8StringEncoding];