Question

Am getting this problem which I have commented in my main file:

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

int main (int argc, const char * argv[])
{

    // Create an instance of Person
    Person *person = [[Person alloc]init];

    // Give the instance variables interesting values
    [person setWeightInKilos:96];
    [person setHeightInMeters:1.8];

    // Call the body mass index
    float bmi = [person bodyMassIndex];
    NSLog(@"person has a bmi of %f", bmi);

    }
    return 0;                           // Expected identifier or '('
 }                                       // Expected external declaration

Person.h

#import <Foundation/Foundation.h>

@interface Person : NSObject {
    float heightInMeters;
    int weightInKilos;
}

// You will be able to set those instance variables using these methods
- (void)setHeightInMeters:(float)h;
- (void)setWeightInKilos:(int)w;

// This method calculates the body weight index
- (float)bodyMassIndex;

@end

Person.m

#import "Person.h"

@implementation Person

- (void)setHeightInMeters:(float)h{
    heightInMeters = h;  
}

- (void)setWeightInKilos:(int)w {
    weightInKilos = w;
}

- (float)bodyMassIndex {
    return weightInKilos / (heightInMeters * heightInMeters);  
}

@end

Answer 1

You have a stray } in your program before the return 0;. The error is rather misleading. You may want to switch over to using LLVM instead of GCC (this will get you faster compilation too, not just better errors).