alloc and init have done what verification.

in conclusion:

　　alloc responsible for allocating memory and create objects corresponding isa pointer;

　　alloc init simply returns the object generated.

 　  So after alloc, multiple calls to init, the returned object is the same!

code show as below:

 1 //
 2 //  main.m
 3 //  alloc.initTest
 4 //
 5 //  Created by LongMa on 2019/5/30.
 6 //  Copyright © 2019 hautu. All rights reserved.
 7 //
 8 
 9 #import <Foundation/Foundation.h>
10 
11 int main(int argc, const char * argv[]) {
12     @autoreleasepool {15         
16         NSObject *obj1 = [NSObject alloc];
17         NSLog(@"%p",obj1);
18         
19         NSObject *obj2 = [obj1 init];
20         NSObject *obj3 = [obj1 init];
21         NSLog(@"%p",obj2);
22         NSLog(@"%p",obj3);
23     }
24     return 0;
25 }

operation result:

2019-05-30 09: 35: 37.019843 + 0800 alloc.initTest [65183: 12003258] 0x10065d810

2019-05-30 09: 35: 37.019864 + 0800 alloc.initTest [65183: 12003258] 0x10065d810

2019-05-30 09: 35: 37.019874 + 0800 alloc.initTest [65183: 12003258] 0x10065d810

Program ended with exit code: 0

 

Inspired Article Reference: http: //www.cocoachina.com/ios/20190527/27009.html