@implementation NSObject (loadAndInitial)

+ (void)initializeAndLog {

    NSLog(@"**out- %s %@",__func__,[self class]);

    [self initializeAndLog];

}

+ (void)load{

    NSLog(@"%s",__func__);

    Method method1 = class_getClassMethod([self class

    Method method2 = class_getClassMethod([self class], @selector(initializeAndLog));

    //交換method1和麼thod的IMP指標，(IMP代表了方法的具體的實現）

    method_exchangeImplementations(method1, method2);

}