Foundation for IOS development

The foundation framework is the foundation layer for accessing basic data types, collections, and operating system services to define application functions.

The foundation framework provides basic functions for applications and frameworks, including data storage and persistence, text processing, date and time calculation, sorting and filtering, and networking. Foundation defined classes, protocols, and data types are used throughout the MacOS, IOS, watchos, and tvos SDKs.

1、 Basic content

1、Numbers, Data, and Basic Values

Raw values and other basic data types used in cocoa.

2、Strings and Text

Creates and processes strings of Unicode characters, uses regular expression lookup patterns, and performs natural language analysis on text.


Use arrays, dictionaries, collections, and private collections to store and iterate groups of objects or values.

4、Dates and Times

Compare dates and times, and perform calendar and time zone calculations.

5、Units and Measurement

Dimension numeric quantities with physical dimensions to allow conversion between locale formats and related units.

6、Data Formatting

Converts numbers, dates, measures, and other values to a string representation that recognizes the locale.

7、Filters and Sorting

Use predicates, expressions, and sort descriptors to examine elements in collections and other services.

2、 Application support

1、Task Management

Manage the work of the application and how the application interacts with system services such as handoff and shortcuts.


Access assets and other data bundled with your app.


Design pattern of broadcast information and subscription broadcast.

4、App Extension Support

Manage the interaction between application extensions and their managed applications.

5、Errors and Exceptions

Respond to problems when interacting with the API and fine tune your application for better debugging.

6、Scripting Support

Allows users to use Applescript and other automation technologies to control or run scripts from within your application.

3、 File and data persistence

1、File System

Create, read, write and check files and folders in the file system.

2、Archives and Serialization

Convert objects and values back and forth between attribute lists, JSON, and other flat binary representations.


Permanently store domain wide information to configure your application.


Search for files and other items on your local device and index your app content for search.


Manage files and key data that are automatically synchronized between users' icloud devices.

6、Optimizing App Data for iCloud Backup

Minimize the space and time icloud backup requires for your application data.

4、 Network

1、URL Loading System

Use standard internet protocol to interact with URL and communicate with server.


Advertise services to facilitate discovery on the local network, or services advertised by others.

5、 Underlying utilities


Manage secure interprocess communication.

2、Object Runtime

Get low level support for basic Objective-C functions, cocoa design patterns, and swift integration.

3、Processes and Threads

Manage the interaction of your application with host operating system and other processes, and implement low-level concurrency function.

4、Streams, Sockets, and Ports

Use the underlying UNIX functions to manage the input and output between files, processes and networks.

6、 Others

Foundation Enumerations