1.What is the RAM size in iPhone 4?
512MB
2.Current device resolution?
320X480 for iPhone
1024X720 for iPad
3.what compiler we have used in Objective c?
Compiler for objective c GCC version 4.0
4.SDK:
SDK means software development kit. It contains Xcode IDE,instruments, iPhone simulator,Interface Builder,Frameworks…
5.What are SDK tools in iPhone?
XCode
IB
Simulator
Instruments
6.What is Xcode?
Xcode is an Intigrated Development Environment IDE it acts like an Editor of Objective c loang We can write,run,build our code in xcode
7.What is the simulator?
it is a demo to check our applications if we didn't have the original device
8.what are Instruments:
The instrument enables you to dynamically trace and profile the performance of the Macos,iPhone, iPad applications.
Bu using Instruments we can test the performance of the application.
9.what is Interface Builder:
Interface builder is developed in 1988.It is a visual tool that allows you to design your interfaces for iphone.By using interface builder we can drag and drop the views on interface.
10.Explain about Inspector
It is mainly used for setting the properties of view elements. It contains four sections.
1)Attribute inspector
2)Connection
3)Size of inspector
4)Identity
11.Groups and File sections:
Classes:
In class folder actual coding will be their.
for window based application we have two files.
1)appdelegate.h
2)appdelegate.m
For view based applications we have four files.
1)appdelegate.h
2)appdelegate.m
3)viewcontrol.h
4)viewcontrol.m
12.what are different Layers of iOS
Cocoa Touch Layer
Media Layer
Core Services Layer
Core Services Layer
13.What is optimization?
Optimaisation is nothing but
Making our application more attractively even after complition of the coding
14.What happend if array release?
As such, when the NSArray is released your object will still have a retain count of one and will therefore still be around after the autorelease pool is emptied. (Until of course you release it.
15.How can we use multiple class inheritance in objective c?
In Objective c Multiple inheritance is not supported
for this porpous we use "categories" in Objective c
16.How can u use object for abstract class?
(or) What is Shared Obj?
We can't create object for abstract class
to call abstract class we use Shared obj
17.Garbage collection:
Garbage collection means a memory management system that automatically release memory used by unreferenced variable.
Modern computer langs uses Garbage collection [GC] Gc is a runtime algorithm that scans the allocated objects in our prog and deallocates the obj that we have loss contact. cocoa under the iphone os does not use GC so cocoa apps must use managed memory. applications running on this platform sh'd b clean up after use. since iphone apps run in a memory constraint environment
18.Retain:
It indicates that we can putting the Ownership climb on the object
it increases the Retain count by 1
if the caller releases the object it doesn't deallocated if it is retained
19.Release:
it decreases the retain count by 1
when we call release we r no longer the owner of the obj
if the the reference count is 0
the object will b Deallocated
The memory is freed it will be used by another obj
20.AUTORELEASEPOOL:
all the released objects are added to
the Pool, that pool is nothing but AutoReleasePool
the pool objects are released by keywords release/Drain
21.What is the difference between the dot notation and using the square brackets?
The Dot Syntax only for Setter & Getters
button for the Methods
22.reference counting.
Objective-C's memory management system is called reference counting.
23.How can we deallocates all objects in AutoReleasepool?
difference b/n Drain & Release..?
By Using DRAIN keyword we can deallocate all objects from autoReleasePool
By using Release We can't Deallocate all the objects
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