nsmutablearray

I decided to start using removeAllObjects so that I could re-use some of my NSMutableArrays. However, I am finding that the call to removeAllObjects causes the array to get released and so it crashes when the viewController is displayed for the second time. I've looked on the web and it seems that some people are saying that removeAllObjects just clears their array, while others are saying that it also releases the array. Which is true? It appears to release for me, but I find that weird and would expect the behaviour to be just to release the objects within the array. Nothing in the

For the following code snippet from ViewController.m: - (IBAction)buttonAction:(id)sender { CustomButton *button = (CustomButton *)sender; button.associatedObject = [self.sourceOfObjects.objectArray lastObject]; [self.foo.arrayOfObjects addObject:button.associatedObject]; // this does not work? } • CustomButton is subclass of UIButton and has @property (nonatomic, strong) associatedObject that is a pointer to an object of type NSObject. • sourceOfObjects is a @property (nonatomic, strong) of self of type MyCustomObject, a subclass of NSObject. • objectArray is a @property (nonatomic, strong)

一下内容由 angellixf 整理 , 这里制作记录 : Object-c 代码 /******************************************************************************************* NSString *******************************************************************************************/ // 一、 NSString /*---------------- 创建字符串的方法 ----------------*/ // 1 、创建常量字符串。 NSString *astring = @ "This is a String!" ; // 2 、创建空字符串，给予赋值。 NSString *astring = [[NSString alloc] init]; astring = @ "This is a String!" ; [astring release]; NSLog(@ "astring:%@" ,astring); // 3 、在以上方法中，提升速度 :initWithString 方法 NSString *astring = [[NSString alloc] initWithString:@

NSMutableArray 是 NSArray 的一个子类，因此可以在任何使用 NSArray 的位置使用 NSMutableArray。 除了包含在 NSArray 中的方法，NSMutableArray 还提供了修改数组的方法。 // 向数组添加对象 addObject: 和 insertObject:atIndex: // 从数组删除对象 removeAllObjects、removeLastObject 和 removeObjectAtIndex: //替换数组中的某个对象 replaceObjectAtIndex:withObject: //筛选数组 filterUsingPredicate: //重新排列数组中的元素 exchangeObjectAtIndex:withObjectAtIndex:、sortUsingComparator:和sortUsingFunction: context: ps: 数组类 NSArray 和 NSMutableArray 仅能包含对象。 不能将标量数据类型，如 int、long 或者其他任何不是继承自 NSObject 的类型插入 NSArray 或 NSMutableArray。 来源： oschina 链接： https://my.oschina.net/u/2320053/blog/506941

For example: I have two NSMutableArray . One @[1,2,3,4,5,6,7] . Other have objects like @[ @{@idObjectToSearch":1, @"name":@"aaaaa", @"surname": @"bbbbb"}, @{@idObjectToSearch":2, @"name":@"aaaaa", @"surname": @"ccccc"}, ... @{@idObjectToSearch":100, @"name":@"aaaaa", @"surname": @"cccdcd"} ]; So how I could extract needed objects from second array more effective way? You need to use NSPredicate with your second array. NSPredicate *predicate = [NSPredicate predicateWithFormat:@"idObjectToSearch IN %@", firstArray]; //In above predicate instead of passing `1` you need to pass object from first