iOS Development--Interview written essence (iii)

Interview written essence (iii)

1. When is the use of Nsmutablearray and when to use Nsarray? When to use Nsmutablearray, when to use Nsarray?

1> when an array element needs to be dynamically added or deleted, use Nsmutablearray

2> when the array element is fixed, use the Nsarray

2. Give US example of what is delegate methods and what is data source methods of UITableView. Give an instance of the delegate method and say the UITableView data source method

1> Proxy method: Returns the height of the TableView per row, listening TableView the selection of each row

2> Data Source method: Returns the number of groups and rows of tableview data, and what data is displayed per row

3> UITableView's data source method has-(Nsinteger) TableView: (UITableView *) TableView numberofrowsinsection: (Nsinteger) Section

4>-(UITableViewCell *) TableView: (UITableView *) TableView Cellforrowatindexpath: (Nsindexpath *) Indexpath;

3. How many autorelease can create in your application? Is there any limit? How many Autorelease objects can be created in the app, and is there a limit?

No Limits

4. If we don ' t create any autorelease pool with our application then be there any autorelease pool already provided to us? If we do not create a memory pool, do we have a memory pool available to us?

Auto-free pools are created and destroyed by default on an unscheduled basis

5. When do you'll create an autorelease pool in your application? When do I need to create a memory pool in my program?

When you need to precisely control the release time of an object, you need to manually create an auto-release pool

6. When retain count increase? When will memory count increase?

As a retain or copy operation, it is possible to increase the counter

7. What is commonly used NSObject class methods? Which methods of class nsobject are often used?

NSObject Common class methods are: Alloc, new, description, etc.

8. What is convenience constructor? What is a simple construction method?

Like Nsstirng's Stringwithformat,nsnumber numberwithint.

9. How to design universal application in Xcode? How do I design a generic app with Xcode?

1> When you create a project, device selects Universal

2> can create a common set of data models

3> Select different controllers according to Iphone\ipad (ipad may use Uisplitviewcontroller)

4> choose a different interface according to Iphone\ipad

Keyword atomic in Objective C? In Objetive-c What is the Atomic keyword

1> Atomic is atomic

2> Atomic will lock the implementation of the Set method

What is UIView animations? UIView's animated effects have those

The core animation of the UIView package can be implemented through the class method \block

How can I store data in IPhone applications? How do I save data in the iphone app?

1> Property List

2> Preference (Nsuserdefaults)

3> Key-Value archive (Nskeyedarchiver, nscoding)

4> SQLite Database

5> Core Data

What is Nsmanagedobject model? What is a nsmanagedobject model?

Nsmanagedobject is the entity object in core data

What is predicate? What is a predicate?

Predicate: You can filter the collection data of array, dictionary and so on with certain conditions, also can be used in the data query of core

iOS Development--Interview written essence (iii)