#import <Foundation/Foundation.h>

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

    @autoreleasepool {
       
        NSString *str1 = @"This is a NSString string";
        NSData *str2 = [str1 dataUsingEncoding:NSASCIIStringEncoding];
        char const *str3 = str2.bytes;
       
        printf("Our C string is: %s", str3);
       
    }
    return 0;
}

#import <Foundation/Foundation.h>

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

    @autoreleasepool {
   
    NSMutableArray *array1 = [NSMutableArray array];
   
    NSString *element;
    NSString *string1 = [NSString stringWithFormat:@"This is a string"];
    NSMutableString *string2 = [NSMutableString stringWithFormat:@"This is a mutable string"];
    NSMutableString *string3 = [NSMutableString stringWithFormat:@"This is another mutable string"];
   
    NSURL *url1 = [NSURL URLWithString: [NSString stringWithFormat:@"http://www.freebsdonline.com"]];
    NSProcessInfo *process1 = [NSProcessInfo processInfo];
    NSMutableDictionary *dict1 = [NSMutableDictionary dictionary];
    
    [dict1 setObject:@"casa" forKey:@"house"];
    [dict1 setObject:@"gato" forKey:@"cat"];
    [dict1 setObject:@"perro" forKey:@"dog"];
    [dict1 setObject:@"ratón" forKey:@"mouse"];
       
    [array1 addObject:string1];
    [array1 addObject:string2];
    [array1 addObject:string3];
    [array1 addObject:url1];
    [array1 addObject:process1];
    [array1 addObject:dict1];   
   
    BOOL isMember;
    BOOL isKind;
    BOOL respondsToSelector;
       
    for (element in array1) {
        isMember = NO;
        isKind = NO;
        respondsToSelector = NO;
        NSLog(@"Name of the class: %@", [element className]);
        if ([element isMemberOfClass:[NSString class]]) {
            isMember = YES;
        }
       
        NSLog(@"Class is member of NSString: %@", isMember?@"YES":@"NO");
       
        if ([element isKindOfClass:[NSString class]]) {
            isKind = YES;
        }
       
        NSLog(@"Class is kind of NSString: %@", isKind?@"YES":@"NO");

     
        SEL selector1 = @selector(uppercaseString);
        if ([element respondsToSelector:selector1]) {
            respondsToSelector = YES;
        }
        NSLog(@"Class responds touppercaseString: %@", respondsToSelector?@"YES":@"NO");
       
        NSLog(@"------------------------------------");
    }
       
    }
    return 0;
}

#import <Foundation/Foundation.h>

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

    @autoreleasepool {
        NSLog(@"Display elements of an array");
        NSString *element;
        NSMutableArray *array;
       
        array = [NSMutableArray arrayWithObjects:@"value1", @"value2", @"value3", nil];
       
        for (element in array) {
            NSLog(@"%@",element);
        }
    }
    return 0;
}

#import <Foundation/Foundation.h>

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

    @autoreleasepool {
       
        NSLog(@"Play With Strings");
       
        NSDictionary *dict = [NSDictionary dictionaryWithObjectsAndKeys:
            @"casa", @"house",
            @"gato", @"cat",
            @"perro", @"dog",
            @"ratón", @"mouse",
            nil];
       
        // Display an element of the dictionary using a key
        NSString *word = [dict objectForKey:@"dog"];
        NSLog(@"Spanish word for 'dog' is: %@", word);
       
        // Iterate through dictionary
        NSEnumerator *enumerate = [dict objectEnumerator];
        id val;
       
        int count=1;

        // First Variant, print values
        while ((val = [enumerate nextObject])) {
            NSLog(@"Word %d: %@",count, val);
            count++;
        }

        // Second Variant, print values and keys
        for (id key in dict) {
            NSString *val2 = [dict objectForKey:key];
            NSLog(@"Key(english): %@, Value(spanish): %@", key, val2);           
        }
    }
    return 0;
}

#import <Foundation/Foundation.h>

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

    @autoreleasepool {
       
        NSLog(@"Display elements of an array");
        NSString *element;
        NSArray *array;
       
        array = [NSArray arrayWithObjects:@"value1", @"value2", @"value3", nil];

        for (element in array) {
            NSLog(@"%@",element);
        }
    }
    return 0;
}

#import <Foundation/Foundation.h>

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

    @autoreleasepool {
       
        NSLog(@"Path Examples");
        NSString *path1 = @"/usr/local/bin";
        NSString *path2 = @"~";
        NSString *path3 = @"/usr/local/../";
        NSString *path4 = @"/usr//local//bin/";
        NSString *path5 = @"/usr/./local/./bin/";
       
        NSString *path_full;
       
        path_full = [path1 stringByStandardizingPath];
        NSLog(@"path1 is: %@", path_full);

        path_full = [path2 stringByStandardizingPath];
        NSLog(@"path2 is: %@", path_full);

        path_full = [path3 stringByStandardizingPath];
        NSLog(@"path3 is: %@", path_full);

        path_full = [path4 stringByStandardizingPath];
        NSLog(@"path4 is: %@", path_full);

        path_full = [path5 stringByStandardizingPath];
        NSLog(@"path5 is: %@", path_full);
    }
    return 0;
}

#import <Foundation/Foundation.h>

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

    @autoreleasepool {
       
        NSLog(@"Play With Strings");
       
        NSString *str1 = @"This is a string!";
        NSString *str2 = @"This is another string!";

        NSLog(@"Our strings are: %@ %@", str1, str2);

    }
    return 0;
}