Testing different ways of defining Objective-C variables

objc_memory.m

@interface VariableNoBrackets : NSObject
@end
@implementation VariableNoBrackets
NSString *aString;

- (instancetype)initWithString: (NSString *)newString {
    self = [super init];
    if (self) {
        aString = newString;
    }
    return self;
}

- (NSString *)description {
    return [NSString stringWithFormat:@"VariableNoBrackets string: %@ stringInstance %p", aString, aString];
}
@end


@interface VariableWithBrackets : NSObject
@end
@implementation VariableWithBrackets {
    NSString *_anotherString;
}

- (instancetype)initWithString: (NSString *)anotherString {
    self = [super init];
    if (self) {
        _anotherString = anotherString;
    }
    return self;
}

- (NSString *)description {
    return [NSString stringWithFormat:@"VariableWithBrackets string: %@ stringInstance %p", _anotherString, _anotherString];
}
@end


@interface VariableAccess : NSObject
@end
@implementation VariableAccess

- (NSString *)description {
    return [NSString stringWithFormat:@"VariableAccess string: %@ stringInstance %p", aString, aString];
}
@end


@interface UsingProperty : NSObject
@property NSString *propertyString;
@end
@implementation UsingProperty
- (instancetype)initWithString: (NSString *)aPropertyString {
    self = [super init];
    if (self) {
        self.propertyString = aPropertyString;
    }
    return self;
}

- (NSString *)description {
    return [NSString stringWithFormat:@"PropertyString string: %@ stringInstance %p", self.propertyString, self.propertyString];
}
@end


Test:
    VariableNoBrackets *noBrackets1 = [[VariableNoBrackets alloc] initWithString: @"abc"];
    VariableNoBrackets *noBrackets2 = [[VariableNoBrackets alloc] initWithString: @"def"];
    NSLog(@"no brackets %@", noBrackets1);
    NSLog(@"no brackets %@", noBrackets2);
    
    VariableWithBrackets *withBrackets1 = [[VariableWithBrackets alloc] initWithString: @"123"];
    VariableWithBrackets *withBrackets2 = [[VariableWithBrackets alloc] initWithString: @"456"];
    NSLog(@"with brackets %@", withBrackets1);
    NSLog(@"with brackets %@", withBrackets2);
    
    VariableAccess *access1 = [[VariableAccess alloc] init];
    VariableAccess *access2 = [[VariableAccess alloc] init];
    NSLog(@"with access %@", access1);
    NSLog(@"with access %@", access2);

    UsingProperty *prop1 = [[UsingProperty alloc] initWithString: @"ABCDEF"];
    UsingProperty *prop2 = [[UsingProperty alloc] initWithString: @"DEFGHI"];
    NSLog(@"with property %@", prop1);
    NSLog(@"with property %@", prop2);
    

Results:
2014-05-15 18:45:53.158 DerekSpike[5485:60b] no brackets VariableNoBrackets string: def stringInstance 0x6c91c // static
2014-05-15 18:45:53.160 DerekSpike[5485:60b] no brackets VariableNoBrackets string: def stringInstance 0x6c91c // static
2014-05-15 18:45:53.161 DerekSpike[5485:60b] with brackets VariableWithBrackets string: 123 stringInstance 0x6c93c // instance
2014-05-15 18:45:53.162 DerekSpike[5485:60b] with brackets VariableWithBrackets string: 456 stringInstance 0x6c94c // instance
2014-05-15 18:45:53.163 DerekSpike[5485:60b] with access VariableAccess string: def stringInstance 0x6c91c // static, global (at least within the file)
2014-05-15 18:45:53.164 DerekSpike[5485:60b] with access VariableAccess string: def stringInstance 0x6c91c // static, global
2014-05-15 18:45:53.165 DerekSpike[5485:60b] with property PropertyString string: ABCDEF stringInstance 0x6c97c // instance
2014-05-15 18:45:53.167 DerekSpike[5485:60b] with property PropertyString string: DEFGHI stringInstance 0x6c98c // instance