Filter an NSArray which contains custom objects

问题

I have UISearchBar, UITableView, a web service which returns a NSMutableArray that contain objects like this:

//Food.h
Food : NSObject { 
    NSString *foodName;
    int idFood;
}

@property (nonatomic, strong) NSString *foodName;

And the array:

Food *food1 = [Food alloc]initWithName:@"samsar" andId:@"1"];
Food *food2 = [Food alloc] initWithName:@"rusaramar" andId:@"2"];

NSSarray *array = [NSArray arrayWithObjects:food1, food2, nil];

How do I filter my array with objects with name beginning with "sa"?

回答1:

You can filter any array like you'd like to with the following code:

NSMutableArray *array = ...;

[array filterUsingPredicate:[NSPredicate predicateWithBlock:^BOOL(id evaluatedObject, NSDictionary *bindings) {
    return [evaluatedObject.foodName hasPrefix:searchBar.text];
}];

This will filter the array "in-place" and is only accessible on an NSMutableArray. If you'd like to get a new array that's been filtered for you, use the filteredArrayUsingPredicate: NSArray method.

回答2:

NSString *predString = [NSString stringWithFormat:@"(foodName BEGINSWITH[cd] '%@')", @"sa"];

NSPredicate *pred = [NSPredicate predicateWithFormat:predString];

NSArray *array = [arr filteredArrayUsingPredicate:pred];
NSLog(@"%@", array);

来源：https://stackoverflow.com/questions/9558335/filter-an-nsarray-which-contains-custom-objects