Question

如何检查NSArray上的最后一个对象中的对象？

我试过了：

if ([currentStore isEqual:[Stores lastObject]])
{
  //Code
}

但它不起作用。

有什么想法吗？

谢谢！

Answer 1

或试试这个

BOOL lastElement = false;
NSUInteger index = [stores indexOfObject:currentStore];
if (index != NSNotFound)
{
    lastElement = (index == [stores count] - 1);
}

Answer 2

比特修改试试这个：

 NSUInteger index = [stores indexOfObject:currentStore];
            if (index == ([stores count]-1))
            {
                NSLog(@"Yes its Last");
            }

Answer 3

如果你没有覆盖isEqual方法，NSObject :: isEqual的基类实现只检查两个指针是否指向同一个地址。

这篇优秀的文章http://nshipster.com/equality/解释了objc平等原则

以下示例日志 - 测试商店 - 工作正常

@interface Stores : NSObject

@property (strong, nonatomic) NSString* name;

- (instancetype) initWithName:(NSString*) name;

@end

@implementation Stores

- (instancetype) initWithName:(NSString*) name;
{
    _name = name;
    return self;
}


- (BOOL)isEqualToStores:(Stores*) Stores
{
    if (!Stores)
        return NO;

    if (![_name isEqualToString:Stores.name] )
        return NO;

    return YES;
}

- (BOOL)isEqual:(id)object
{
    if (self == object)
    {
        return YES;
    }

    if (![object isKindOfClass:[Stores class]])
    {
        return NO;
    }

    return [self isEqualToStores:(Stores *)object];
}

@end

-(void) testStores
{
    Stores* last = [[Stores alloc] initWithName:@"5"];
    NSArray* arr = @[
                     [[Stores alloc] initWithName:@"1"],
                     [[Stores alloc] initWithName:@"2"],
                     [[Stores alloc] initWithName:@"3"],
                     [[Stores alloc] initWithName:@"4"],
                     [[Stores alloc] initWithName:@"5"]
                     //last
                    ];

    if ([last isEqual:[arr lastObject]])
    {
        NSLog(@"Testing Stores - works fine");
    }
    else
    {
        NSLog(@"Testing Stores - opps!?1?!?");
    }
}

如何检查对象是否是NSArray上的最后一个对象

3 个答案: