每日一练:OC中的对象概念-堆的内存管理

#import <Foundation/Foundation.h>

int main(int argc, const char * argv[]) {

    @autoreleasepool {

        // insert code here...

//        NSLog(@"Hello, World!");

        NSDate *currentTime = nil;

        NSLog(@"Current Time is %p", currentTime);

        

        NSDate *newDate = [NSDate date];

        NSLog(@"The new date is %p \n", newDate);

        //复制到新的对象

        NSDate *startDate = newDate;

        NSLog(@"The start date is %p \n", startDate);

        

        sleep(5);

        //重置成新的对象

        newDate = [NSDate date];

        NSLog(@"The latest date is now changed to %p \n", newDate);

        

        //销毁对象

        newDate = nil;

        NSLog(@"Now, the new date had been updated to %p \n", newDate);

        

    }

    return 0;

}

Result：

2018-03-10 21:56:58.704032+0800 TOCObjectivea[52371:13638298] Current Time is 0x0

2018-03-10 21:56:58.704302+0800 TOCObjectivea[52371:13638298] The new date is 0x1007119a0

2018-03-10 21:56:58.704330+0800 TOCObjectivea[52371:13638298] The start date is 0x1007119a0

2018-03-10 21:57:03.707665+0800 TOCObjectivea[52371:13638298] The latest date is now changed to 0x10070ca10

2018-03-10 21:57:03.708026+0800 TOCObjectivea[52371:13638298] Now, the new date had been updated to 0x0

Program ended with exit code: 0