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NSPredicate谓词过滤的简单使用
NSArray *firstNames = @[ @"Alice", @"Bob", @"Charlie", @"Quentin" ];
NSArray *lastNames = @[ @"Smith", @"Jones", @"Smith", @"Alberts" ];
NSArray *ages = @[ @24, @27, @33, @31 ];
NSMutableArray *people = [NSMutableArray array];
[firstNames enumerateObjectsUsingBlock:^(id obj, NSUInteger idx, BOOL *stop) {
Person *person = [[Person alloc] init];
person.firstName = firstNames[idx];
person.lastName = lastNames[idx];
person.age = ages[idx];
[people addObject:person];
}];
NSPredicate *bobPredicate = [NSPredicate predicateWithFormat:@"firstName = 'Bob'"];
NSPredicate *smithPredicate = [NSPredicate predicateWithFormat:@"lastName = %@", @"Smith"];
NSPredicate *thirtiesPredicate = [NSPredicate predicateWithFormat:@"age >= 30”];
// ["Bob Jones"]
NSLog(@"Bobs: %@", [people filteredArrayUsingPredicate:bobPredicate]);
// ["Alice Smith", "Charlie Smith"]
NSLog(@"Smiths: %@", [people filteredArrayUsingPredicate:smithPredicate]);
// ["Charlie Smith", "Quentin Alberts"]
NSLog(@"30's: %@", [people filteredArrayUsingPredicate:thirtiesPredicate]);
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