In this, we make a copy of the object, but without actually doing it bit by bit - we want an object that behaves the same for all intents and purposes, but isn't (necessarily) a memory-identical clone of the original - the Objective C manual calls such an object "functionally indepen...
clear notarised copy clear overlay clear photograph clear pied clear responsibilitie clear skies icicle clear sky over the mo clear stocks clear the air clear the goods for e clear up after rain o clear wisdom clear-cut photocathod clear-energy clearance agent clearance compenstati clearance gap ...
common nandina branch common nighthawk common object request common ownership common pistache leaf common plant common potentiometer common power section common quality testin common redshanktringa common reference common resin common rosefinch carp common round iron nai common sailer neptis common salt co...
a unit of data in object-oriented programming. The resulting object iscalled an object copy or simply copy of the original object. Copying is basicbut has subtleties and can have significant overhead. There are several ways tocopy an object, most commonly by a copy constructor or cloning. Co...
一、从面向对象到Objective-C概览copy 1、面向对象: In object-oriented programming, object copying is creating a copy of an existing object, a unit of data in object-oriented programming. The resulting object is called an object copy or simply copy of the original object. Copying is basic but ...
一、从面向对象到Objective-C概览copy 1、面向对象: In object-oriented programming, object copying is creating a copy of an existing object, a unit of data in object-oriented programming. The resulting object is called an object copy or simply copy of the original object. Copying is basic but ...
也就是说,retain是指针拷贝,copy是内容拷贝。在拷贝之前,都会释放旧的对象。 1、使用copy: 对NSString 2、使用retain: 对其他NSObject和其子类 strong与weak是由ARC新引入的对象变量属性 ARC引入了新的对象的新生命周期限定,即零弱引用。如果零弱引用指向的对象被deallocated的话,零弱引用的对象会被自动设置为nil...
memccpy() — Copy bytes in memory memchr() — Search buffer memcmp() — Compare bytes memcpy() — Copy buffer memmove() — Move buffer memset() — Set buffer to value m_getvalues_layout() — Query layout values of a layout object (bidi data) mkdir() — Make a directory ...
object-c语言的nonatomic,assign,copy,retain的区别 nonatomic: 非原子性访问,不加同步,多线程并发访问会提高性能。如果不加此属性,则默认是两个访问方法都为原子型事务访问。 (atomic是Objc使用的一种线程保护技术,基本上来讲,是防止在写未完成的时候被另外一个线程读取,造成数据错误。而这种机制是耗费系统资源的,...
Object-c中的copy关键字 copy 只会产生不可变的副本对象(比如NSString) mutableCopy 只会产生可变的副本对象(NSMutableString) | 源对象类型 |拷贝方法 | 副本对象类型 |是否产生了新对象| 拷贝类型 | | --- |:---:| | NSString | copy | NString...