StackOverflow2013

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copied!<p>Your code lacks autoreleasepools :D this means you're storing 1000 MyEntity objects in memory, and this WILL lead to crashes and iOS will FC your app (force close). The code should look like:</p> <pre><code>for(int i = 0; i < 1000; i++) { @autoreleasepool { MyEntity *object = [NSEntityDescription insertNewObjectForEntityForName:@"MyEntity" inManagedObjectContext:[self managedObjectContext]]; object.name = [NSString stringWithFormat:@"%d", i]; object.age = [NSNumber numberWithInt:i]; } } [self managedObjectContext] save:nil]; </code></pre> <p>OR:</p> <pre><code>for(int i = 0; i < 1000; i++) { NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init]; MyEntity *object = [NSEntityDescription insertNewObjectForEntityForName:@"MyEntity" inManagedObjectContext:[self managedObjectContext]]; object.name = [NSString stringWithFormat:@"%d", i]; object.age = [NSNumber numberWithInt:i]; [pool drain]; } [self managedObjectContext] save:nil]; </code></pre> <p>Also, this may not be the best way to do this kind of thing, I would suggest adding it to the context, then operating on the context itself perhaps using </p> <p><code>[[NSEntityDescription entityForName:@"MyEntity" inManagedObjectContext:managedObjectContext] name] = [NSString stringWithFormat:@"%d", i];</code> </p> <p>or something of the sort. This way you don't create a local copy of the object and clog up your memory.</p> <p>Using the last of three methods, I would do it like this:</p> <pre><code>for(int i = 0; i < 1000; i++) { [NSEntityDescription insertNewObjectForEntityForName:@"MyEntity" inManagedObjectContext:[self managedObjectContext]]; [[NSEntityDescription entityForName:@"MyEntity" inManagedObjectContext:managedObjectContext] name] = [NSString stringWithFormat:@"%d", i]; [[NSEntityDescription entityForName:@"MyEntity" inManagedObjectContext:managedObjectContext] age] = [NSNumber numberWithInt:i]; } [self managedObjectContext] save:nil]; </code></pre> <p>And if this MyEntity is your own custom class, you can even simplify your code by using</p> <pre><code>@property(nonatomic, retain) id name; @property(nonatomic, retain) id age; </code></pre> <p>Replace <code>id name</code> and <code>id age</code> with the correct variable and object class, and this way your code will be even simpler:</p> <pre><code>for(int i = 0; i < 1000; i++) { [NSEntityDescription insertNewObjectForEntityForName:@"MyEntity" inManagedObjectContext:[self managedObjectContext]]; [[NSEntityDescription entityForName:@"MyEntity" inManagedObjectContext:managedObjectContext] setName: [NSString stringWithFormat:@"%d", i]]; [[NSEntityDescription entityForName:@"MyEntity" inManagedObjectContext:managedObjectContext] setAge: [NSNumber numberWithInt:i]]; } [self managedObjectContext] save:nil]; </code></pre> <p>Hope this helps and doesn't confuse you!</p>

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