objective-c - 从 NSMutableArray 中删除对象

Question

我试图删除索引 1 处的对象，但代码无法编译。

我也不明白这一点:我将“iphone”字符串设置为索引 0，之后我将其从索引 0 中删除，但输出仍然首先显示“iphone”。谁能帮我解释一下吗？

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

        //create three string objetc
        NSString *banana  = @"This is banana";
        NSString *apple = @"This is apple";
        NSString *iphone =@"This is iPhone";

        //create  an empty array
        NSMutableArray *itemList = [NSMutableArray array];

        // add the item to the array
        [itemList addObject:banana];
        [itemList addObject:apple];

        // put the iphone to the at first

        [itemList insertObject:iphone atIndex:0];

        for (NSString *l in itemList) {
            NSLog(@"The  Item in the list is %@",l);
        }
        [itemList removeObject:0];
        [itemList removeObject:1];// this is not allow  it

        NSLog(@"now the first item in the list is %@",[itemList objectAtIndex:0]);
        NSLog(@"now the second time in the list is %@",[itemList objectAtIndex:1]);
        NSLog(@"now the thrid item in the list is %@",[itemList objectAtIndex:2]);

    }
    return 0;
}

Answer 1

应该是这样

[itemList removeObjectAtIndex:0];
[itemList removeObjectAtIndex:1];

这个方法在NSMutableArray的文档中有明确的说明。在提出问题之前，请务必查阅适当的文档。