1 void arrayCreate()2 {3     NSMutableArray *array = [NSMutableArray arrayWithObject:@"1"];4    5     [array addObject:@"2"];6     [array addObject:@"3"];7    8     [array removeObject:@"2"];9     NSLog(@"%@", array);
10 }

 1 void memoryManage()2 {3     NSMutableArray *array = [NSMutableArray array];4     Student *stu1 = [Student initWithAge:12];5     Student *stu2 = [Student initWithAge:42];6    7     //Will retain stu1 one time automatically8     [array addObject:stu1];9     [array addObject:stu2];
10
11     NSLog(@"add--> stu1: %zi", [stu1 retainCount]);
12
13     //Will release stu1 one time automatically
14     [array removeObject:stu1];
15     NSLog(@"remoe--> stu1: %zi", [stu1 retainCount]);
16
17     NSLog(@"%@", array);
18
19     //All element will be released one time
20     [array release];
21 }

1 void replaceArray()
2 {
3     NSMutableArray  *array = [NSMutableArray arrayWithObjects:@"1", @"2", @"3", nil];
4     [array replaceObjectAtIndex:2 withObject:@"a"];
5     NSLog(@"%@", array);
6 }

1 void arraySort()
2 {
3     NSMutableArray *array = [NSMutableArray arrayWithObjects:@"1", @"3", @"3", nil];
4     [array sortedArrayUsingSelector:@selector(compare:)];
5     NSLog(@"%@", array);
6 }

1         NSMutableArray *a = [NSMutableArray array];
2         [a addObject:@1];
3         [a addObject:@2];
4         [a removeObject:@1];
5         NSLog(@"%@", a);
6         [a removeAllObjects];
7         NSLog(@"%@", a);