在NSMutableArray的特定索引处添加对象

Question

如何在一个特定的索引处添加一个对象NSMutableArray？

如何将对象添加到数组的前面？

Answer 1

[myMutableArray insertObject:myObject atIndex:42];

要将对象添加到数组的前面,请使用0作为索引:

[myMutableArray insertObject:myObject atIndex:0];

Answer 2

看一下NSMutableArray类的insertObject:atIndex:方法.添加到数组的"前"意味着索引0.

例如:

NSMutableArray * array = [[NSMutableArray alloc] initWithCapacity:3];
[array addObject:@"b"]; // Contains "b"
[array insertObject:@"a" atIndex:0]; // Contains "a", "b"
[array insertObject:@"c" atIndex:2]; // Contains "a", "b", "c"