为什么我们要为@property声明变量 [英] Why should we declare variables for @property

问题描述

我是Objective的新手.当我阅读许多教程时，@ property具有类型的变量，@ inferface中也声明了相同的变量.这需要吗?

I am newbie in Objective. As I read many tutorial, @property has a variable for a type, the same variable is declared in @inferface too. Is this needed?

示例

@interface MyInterface : NSObject
{
   NSInteger myVaribale;
}
@property(retain) NSInteger myVariable; 

在这两个地方都声明了myVariable.

Here myVariable is declared in both place.

推荐答案

自iOS 4起，您可以编写

since iOS 4, you can write

@interface MyInterface : NSObject {
}

@property(assign) NSInteger myVariable; 

@implementation MyInterface
@synthesize myVariable;
@end

这意味着您可以在接口声明中省略NSInteger myVaribale，只要在.m中进行合成即可(合成将创建setter，getter和instance变量)

Meaning you can omit the NSInteger myVaribale in your interface declaration as long as you synthesize it in the .m (the synthesize will create setter, getter and instance variable)

缺点是您不会在Xcode的调试器中看到myVariable的值.

A drawback is that you won't see the value of myVariable in Xcode's debugger.

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