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authorLevi Bostian <levi.bostian@gmail.com>2014-01-06 19:16:47 -0600
committerLevi Bostian <levi.bostian@gmail.com>2014-01-06 19:25:31 -0600
commitd935f8fd4e09a2e72a679d75b732d18e451eaf8a (patch)
tree1b329aa1f620413a04c3be65e199deb928c5b59a /objective-c.html.markdown
parent527fc37efa9cdd9881a2afa3b5e217b91a12db9e (diff)
Edit code for all snippets to compile properly. Re-word some descriptions.
Diffstat (limited to 'objective-c.html.markdown')
-rw-r--r--objective-c.html.markdown44
1 files changed, 22 insertions, 22 deletions
diff --git a/objective-c.html.markdown b/objective-c.html.markdown
index 248e132e..53f155a6 100644
--- a/objective-c.html.markdown
+++ b/objective-c.html.markdown
@@ -76,16 +76,16 @@ int main (int argc, const char * argv[])
short fortyTwoShort = [fortyTwoShortNumber shortValue]; // or 42
NSLog(@"%hi", fortyTwoShort);
- NSNumber *fortyTwoShortNumber = [NSNumber numberWithShort:41];
- unsigned short fortyTwoUnsigned = [fortyTwoShortNumber unsignedShortValue]; // or 41
- NSLog(@"%hu", fortyTwoUnsigned);
+ NSNumber *fortyOneShortNumber = [NSNumber numberWithShort:41];
+ unsigned short fortyOneUnsigned = [fortyOneShortNumber unsignedShortValue]; // or 41
+ NSLog(@"%u", fortyOneUnsigned);
NSNumber *fortyTwoLongNumber = @42L;
long fortyTwoLong = [fortyTwoLongNumber longValue]; // or 42
NSLog(@"%li", fortyTwoLong);
- NSNumber *fortyTwoLongNumber = @53L;
- unsigned long fiftyThreeUnsigned = [fortyTwoLongNumber unsignedLongValue]; // or 53
+ NSNumber *fiftyThreeLongNumber = @53L;
+ unsigned long fiftyThreeUnsigned = [fiftyThreeLongNumber unsignedLongValue]; // or 53
NSLog(@"%lu", fiftyThreeUnsigned);
// Floating point literals
@@ -118,6 +118,7 @@ int main (int argc, const char * argv[])
NSLog(@"%i", yesBool); // prints => 1
// Array object
+ // May contain different data types, but must be an Objective-C object.
NSArray *anArray = @[@1, @2, @3, @4];
NSNumber *thirdNumber = anArray[2];
NSLog(@"Third number = %@", thirdNumber); // Print "Third number = 3"
@@ -148,10 +149,6 @@ int main (int argc, const char * argv[])
[mutableSet addObject:@"Hello"];
NSLog(@"%@", mutableSet); // prints => {(Hello)}
- // Set object
- NSSet *set = [NSSet setWithObjects:@"Hello", @"Hello", @"World", nil];
- NSLog(@"%@", set); // prints => {(Hello, World)}
-
///////////////////////////////////////
// Operators
///////////////////////////////////////
@@ -299,9 +296,9 @@ int main (int argc, const char * argv[])
}
// Convenient notation for public access variables to auto generate a setter method.
// By default, setter method name is 'set' followed by @property variable name.
-@property int count; // Setter name = 'setCount'
+@property int count; // Setter method name = 'setCount'
@property (copy) NSString *name; // (copy) => Copy the object during assignment.
-@property (readonly) id data; // (readonly) => Declare only a getter method.
+@property (readonly) id data; // (readonly) => Cannot set value outside interface.
// You can customize the getter and setter names instead of using default 'set' name:
@property (getter=lengthGet, setter=lengthSet:) int length;
@@ -322,7 +319,7 @@ int main (int argc, const char * argv[])
// automatically. Method name is 'set' followed by @property variable name:
MyClass *myClass = [[MyClass alloc] init]; // create MyClass object instance.
[myClass setCount:10];
-NSLog(@"%@", [myClass count]); // prints => 10
+NSLog(@"%d", [myClass count]); // prints => 10
// Or using the custom getter and setter method defined in @interface:
[myClass lengthSet:32];
NSLog(@"%i", [myClass lengthGet]); // prints => 32
@@ -349,7 +346,7 @@ NSLog(@"%li", distance); // prints => 18
}
// Constructors are a way of creating classes
-// This is a default constructor which is called when the object is creating
+// This is a default constructor which is called when the object is initialized.
- (id)init
{
if ((self = [super init]))
@@ -410,31 +407,34 @@ With all object interactions, follow the pattern of:
(1) create the object, (2) use the object, (3) then free the object from memory.
*/
-MyClass *classVar = [MyClass alloc]; // alloc sets classVar's reference count to one. Returns pointer to object.
+MyClass *classVar = [MyClass alloc]; // 'alloc' sets classVar's reference count to one. Returns pointer to object.
[classVar release]; // Decrements classVar's reference count.
-// retain claims ownership of existing object instance and increments reference count. Returns pointer to object.
+// 'retain' claims ownership of existing object instance and increments reference count. Returns pointer to object.
MyClass *newVar = [classVar retain]; // If classVar is released, object is still in memory because newVar is owner.
[classVar autorelease]; // Removes ownership of object at end of @autoreleasepool block. Returns pointer to object.
-// @property can use retain or assign as well for small convenient definitions.
+// @property can use 'retain' and 'assign' as well for small convenient definitions.
@property (retain) MyClass *instance; // Release old value and retain a new one (strong reference).
@property (assign) NSSet *set; // Pointer to new value without retaining/releasing old (weak reference).
+// Automatic Reference Counting (ARC)
// Because memory management can be a pain, Xcode 4.2 and iOS 4 introduced Automatic Reference Counting (ARC).
// ARC is a compiler feature that inserts retain, release, and autorelease automatically for you, so when using ARC,
// you must not use retain, relase, or autorelease.
-MyClass *arcMyClass = [[MyClass alloc] init]; // Without ARC, you will need to call: [arcMyClass release] after
-// you're done using arcMyClass. But with ARC, there is no need. It will insert this release statement for you.
+MyClass *arcMyClass = [[MyClass alloc] init];
+// ... code using arcMyClass
+// Without ARC, you will need to call: [arcMyClass release] after you're done using arcMyClass. But with ARC,
+// there is no need. It will insert this release statement for you.
-// As for the "assign" and "retain" @property attributes, with ARC you use "weak" and "strong".
-@property (weak) MyClass *weakVar; // weak does not take ownership of object. If original instance's reference count
+// As for the 'assign' and 'retain' @property attributes, with ARC you use 'weak' and 'strong'.
+@property (weak) MyClass *weakVar; // 'weak' does not take ownership of object. If original instance's reference count
// is set to zero, weakVar will automatically receive value of nil to avoid application crashing.
-@property (strong) MyClass *strongVar; // strong takes ownership of object. Ensures object will stay in memory to use.
+@property (strong) MyClass *strongVar; // 'strong' takes ownership of object. Ensures object will stay in memory to use.
// For regular variables (not @property declared variables), use the following:
__strong NSString *strongString; // Default. Variable is retained in memory until it leaves it's scope.
__weak NSSet *weakSet; // Weak reference to existing object. When existing object is released, weakSet is set to nil.
-__unsafe_unretained NSArray *unsafeArray; // Like __weak but unsafeArray not set to nil when existing object is released.
+__unsafe_unretained NSArray *unsafeArray; // Like __weak, but unsafeArray not set to nil when existing object is released.
```
## Further Reading