[iOS]Objective-C 实用特性索引（Objective-C Feature Availability Index）

Objective-C 实用特性索引（Objective-C Feature Availability Index）

本文档分别针对 Xcode 版本以及使用的编译器，还有使用的操作系统版本，将 Objective-C 的各种特性串联起来。

This article correlates features of the Objective-C language with the versions of Xcode and compiler you need to use them, and the OS versions you can use them with.

特性

Feature

工具版本

Tools versions

OS X 部署版本

OS X deployment

iOS 布署版本

iOS deployment

自动引用计数 (ARC)

Automatic Reference Counting (ARC)

Xcode 4.2

(LLVM Compiler 3.0)

Requires modern runtime

Deploys back to OS X v10.7

Deploys back to iOS 5

无归零弱引用的自动引用计数(“ARCLite”)

Automatic Reference Counting without zeroing weak reference (“ARCLite”)

Xcode 4.2

(LLVM Compiler 3.0)

Requires modern runtime

Deploys back to OS X v10.6

Deploys back to iOS 4

默认合成 @property 的实例变量和访问器方法

Default synthesis of @property instance variables and accessor methods

Xcode 4.4

(LLVM Compiler 4.0)

Requires modern runtime

Deploys back to iOS 4

实例变量声明于类扩展中

Instance variables in class extensions

Xcode 4.2

(LLVM Compiler 3.0)

Requires modern runtime

All iOS releases

实例变量声明于 @implementation 实现块

Instance variables in @implementation block

Xcode 4.2

(LLVM Compiler 3.0)

Requires modern runtime

All iOS releases

@implementation 实现块中无需前向方法原型声明

No forward method prototypes needed in @implementation block

Xcode 4.3

(LLVM Compiler 3.1)

All releases

All iOS releases

NSNumber, NSDictionary 和 NSArray 字面值

NSNumber, NSDictionary and NSArray literals

Xcode 4.4

(LLVM Compiler 4.0)

All releases

All iOS releases

布尔值 @YES 和 @NO 字面值

@YES and @NO literals

Xcode 4.4 and OS X 10.8 or later SDK

Xcode 4.5 and iOS 6 or later SDK

(LLVM Compiler 4.0)

All releases

All iOS releases

NSDictionary 和 NSArray 下标


NSDictionary and NSArray subscripting

Xcode 4.4 and OS X 10.8 or later SDK

Xcode 4.5 and iOS 6 or later SDK

(LLVM Compiler 4.0)

Requires modern runtime

Deploys back to OS X v10.6

Deploys back to iOS 4

• “需要现代的运行时” 暗指 64 位系统。

  “Requires modern runtime” implies 64-bit systems.