Question

I am having problems unable to set values taken from UItextfields from a Viewcontroller to another class which does the calculations from those values.

@interface InitialViewController : UIViewController

@property (weak, nonatomic) IBOutlet UITextField *phValue;
@property (weak, nonatomic) IBOutlet UITextField *pco2Value;
@property (weak, nonatomic) IBOutlet UITextField *hco3Value;
@property (weak, nonatomic) IBOutlet UITextField *sodiumValue;
@property (weak, nonatomic) IBOutlet UITextField *chlorideValue;
@property (nonatomic,retain)NSDecimalNumber* ph;
@property (nonatomic,retain) NSDecimalNumber* pco2;
@property (nonatomic,retain)NSDecimalNumber* hco3;
@property (nonatomic,retain)NSDecimalNumber* sodium; 
@property (nonatomic,retain)NSDecimalNumber* chloride;

- (IBAction)analyseValues:(UIButton *)sender;

@end

in the implementation

-(void)values{
[self setPh:[[NSDecimalNumber alloc] initWithFloat:phValue.text.floatValue ]];

[self setPco2:[[NSDecimalNumber alloc] initWithFloat:pco2Value.text.floatValue]];
[self setHco3:[[NSDecimalNumber alloc ] initWithFloat:hco3Value.text.floatValue]];
[self setSodium:[[NSDecimalNumber alloc] initWithFloat:sodiumValue.text.floatValue] ];
[self setChloride:[[NSDecimalNumber alloc] initWithFloat:chlorideValue.text.floatValue] ];
}

- (void)viewDidLoad
{
[super viewDidLoad];
[self values];}

Then I have another class which takes these values ,but on running the program it runs but does assign values taken from the initialViewController.

#import <Foundation/Foundation.h>
#import "InitialViewController.h"

@interface AcidBaseCalculations : NSObject
@property (nonatomic) float ph;
@property (nonatomic) float pco2;
@property (nonatomic) float chloride;
@property (nonatomic) float sodium;
@property (nonatomic) float hco3;

@implementation AcidBaseCalculations

@synthesize ph,pco2,chloride,hco3,sodium;

-(void)calculations{
    InitialViewController *bvc = [[InitialViewController alloc] init]; 
ph = bvc.ph.floatValue ;

pco2 = bvc.pco2.floatValue;     
// these values are not being set although the program   runs successfully

hco3 = bvc.hco3.floatValue;
sodium = bvc.sodium.floatValue;
chloride = bvc.chloride.floatValue;

I want to use these new values here and perform some logical operations in this class.

Answer 1

You are creating a new InitialViewController with this line:

 InitialViewController *bvc = [[InitialViewController alloc] init];

It is a diffrent instance than your other/original InitialViewController

You either have to make a property

 @property(nonatomic,strong)InitialViewController myInitialVC;

And set this property when you are alloc/initing your AcidBaseCalculations.
Our you have to make property for all variables you would like to calculate and set them while alloc/initing to the

AcidBaseCalculations