Objective C

//
//  main.m
//  Objective
//
//  Created by Petko Minkov on 8/20/15.
//  Copyright (c) 2015 Petko. All rights reserved.
//

#import <Foundation/Foundation.h>

@interface Box : NSObject
{
    @public double length;
    @public NSString *name;
}

-(double) volume;
-(id) initWithLength: (int) initLength;
-(id) initWithNameLength: (NSString*) name andLength:(int) length;
-(NSString *) fullTitle;

@end

@implementation Box

-(id) init
{
    length = 15;
    name = @"The box";
    return self;
}

-(id) initWithLength: (int) initLength
{
    length = initLength;
    return self;
}

-(id) initWithNameLength:(NSString *)initName andLength:(int)initLength {
    name = initName;
    length = initLength;
    return self;
}

-(double) volume {
    return length * length;
}

-(NSString *) fullTitle {
    const char *namestr = [name UTF8String];
    NSString *title = [[NSString alloc] initWithFormat:@"Box name: %s, length: %.2f", namestr, length];
    return title;
}

@end

int main(int argc, const char * argv[])
{
    @autoreleasepool {
        NSLog(@"Hello, World!");
        
        Box *box1 = [[Box alloc]initWithNameLength:@"Hello box" andLength:5.2];
        
        int length = box1->length;
        int volume = [box1 volume];
        NSString *title = [box1 fullTitle];
        
        NSLog(@"Length:%d\nVolume:%d\nTitle:%s", length, volume, [title UTF8String]);
    }
    return 0;
}