Runtime - class和object_getClass的区别

class

• 实例对象: 返回对象的isa 即类对象
• 类对象，元类，根元类：返回自己 self

object_getClass

• 返回对象的isa

static inline void classLog(id obj){
    Class cls1 = [obj class];
    Class cls2 = object_getClass(obj);
    NSLog(@"==============================================================");
    NSLog(@"对象:                     %@ %p 是否是元类:%@",obj,obj,class_isMetaClass(obj) ? @"是":@"否");
    NSLog(@"class方法:                %@ %p  是否是元类:%@",cls1,cls1,class_isMetaClass(cls1) ? @"是":@"否");
    NSLog(@"object_getClass方法:      %@ %p  是否是元类:%@",cls2,cls2,class_isMetaClass(cls2) ? @"是":@"否");
    NSLog(@"两个实例是否相等:           %@",[cls1 isEqual:cls2] ? @"是":@"否");
    NSLog(@"==============================================================");
}
- (void)testClass{
    Person *person = [Person new];
    classLog(person);
    Class personClass = object_getClass(person);
    classLog(personClass);
    Class personMetaClass = object_getClass(personClass);
    classLog(personMetaClass);
    Class nsobjectMetaClass = object_getClass(personMetaClass);
    classLog(nsobjectMetaClass);
}