在类中初始化 NSString* 指针的方法 [英] Which way to initialize NSString* pointer in class

问题描述

我在我的类中使用 NSString 并且经常需要将字符串值复制到另一个类.但我的问题是我应该如何初始化字符串，例如 init?(值是类成员，以下调用在 init 中)

I'm using NSString in my classes and often need to copy string value to another class. But my question is how should I initialize string in, for example init? (value is class member and the following calls are in init)

value = [NSString stringWithCString:inStrning encoding:NSASCIIStringEncoding];

或

value = [[NSString alloc] initWithCString:inStrning encoding:NSASCIIStringEncoding];

这里有什么不同?init 完成时是否释放了在第一个调用中分配的内存?我使用 value 作为 assign 属性.使用copy会更好吗?

What is the difference here? Does a memory allocated in 1st call released when init finishes? I'm using value as a assign property. Would it be better to use copy?

当我使用某种方法将字符串传递给类时复制字符串怎么样?示例:

And what about copying string when I'm passing it to class using some method? Example:

-(id) initWithObjectTypeStr:(NSString*)inTypeStr
{
    ...
    objectTypeStr = [NSString stringWithString:inType];
    //or 
    objectTypeStr = [[NSString alloc] initWithString:inType];
}

objectTypeStr 未定义为属性，因此它具有默认属性(我认为是 assign).

objectTypeStr is not defined as property so it has default properties (assign I think).

在这种情况下使用的最佳做法是什么?

What is the best practice to use in this case?

推荐答案

[NSString alloc] initWithString:@""]

归还你拥有的字符串，你必须释放它.

Gives back a string you own, you will have to release it.

[NSString stringWithString:@""]

返回一个自动释放对象，该对象将被自动释放池释放和清理.

Returns an autorelease object that will release and cleaned up by the autoreleasepool.

我建议您阅读 内存管理文档.

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