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NSMutableArray insertObject atIndex

[英]NSMutableArray insertObject atIndex

I have NSMutableArray *myArray = nil; 我有NSMutableArray *myArray = nil; . If I will use [myArray insertObject:@"Hello" atIndex:0] method to this array, will it be allocated automatically? 如果我将[myArray insertObject:@"Hello" atIndex:0]方法用于此数组,它将自动分配吗?

No. It will just send the message to nil. 不会。它只会将消息发送到nil。

It would be equivalent to; 等同于;

[nil insertObject:@"Hello" atIndex:0];

NSMutableArray *nil = [NSMutableArray alloc]init]; NSMutableArray * nil = [NSMutableArray alloc] init];

[nil insertObject:@"How" atIndex:0]; [nil insertObject:@“ How” atIndex:0];

Nope. 不。 Objective-C lets you message nil, so [myArray insertObject:@"Hello" atIndex:0] becomes [nil insertObject:@"Hello" atIndex:0] and will take the fast path in the runtime to doing nothing. Objective-C允许您发送nil消息,因此[myArray insertObject:@"Hello" atIndex:0]变为[nil insertObject:@"Hello" atIndex:0] ,它将在运行时采用快速路径进行任何操作。

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