如何比较像NSPredcate Contains这样的2个NSArray

Question

大家好，这是我的问题

NSArray *recipeIngredientsArray = [recipeIngString componentsSeparatedByCharactersInSet:[NSCharacterSet characterSetWithCharactersInString:@","]];
NSArray  *haveIngArray = [searchText componentsSeparatedByCharactersInSet:[NSCharacterSet characterSetWithCharactersInString:@","]];
if (haveIngArray.count==recipeIngredientsArray.count) 
{       
//check the contents of 2 arrays 
}

我从CoreData中获得了两个数组，如果它们的array length相同，我将检查内容。

在haveIngArray中，我会有像"米饭"、"鸡肉"、"生菜"这样的字符串
在recipeIngredientsArray中，我有"1勺米饭"、"150克鸡肉"、"1杯牛奶"等字符串

recipeIngredientsArray中是否有类似"米饭"one_answers"鸡肉"的字符串？

我尝试将NSPredicate与contain一起使用，但结果不太好。

我对的建议持开放态度

感谢

Answer 1

recipeIngredientsArray不应包含字符串，而应包含其中一个Key/值为@"ingredientName":@"rice"的字典或具有属性name的Ingredient类的更好对象。比谓词查询要容易得多。

#import <Foundation/Foundation.h>
@interface RecipeIngredient : NSObject
@property (nonatomic, copy) NSString *name;
@property (nonatomic, strong) NSNumber *amount;
@property (nonatomic, copy) NSString *unit;
@end

@implementation RecipeIngredient
-(NSString *)description
{
    return [NSString stringWithFormat:@"%@ %@ %@", _amount, _unit, _name];
}
@end

int main(int argc, const char * argv[])
{
    @autoreleasepool {
        NSArray *recipeIngredientsArray = @[
                                            ({
                                                RecipeIngredient *ing = [[RecipeIngredient alloc] init];
                                                ing.amount = @(1);
                                                ing.name = @"rice";
                                                ing.unit = @"spoon";
                                                ing;
                                            }),
                                            ({
                                                RecipeIngredient *ing = [[RecipeIngredient alloc] init];
                                                ing.amount = @(150);
                                                ing.name = @"chicken";
                                                ing.unit = @"gr";
                                                ing;
                                            }),
                                            ({
                                                RecipeIngredient *ing = [[RecipeIngredient alloc] init];
                                                ing.amount = @(1);
                                                ing.name = @"milk";
                                                ing.unit = @"cup";
                                                ing;
                                            }),
                                            ];
        NSArray *haveIngArray = @[@"rice", @"chicken", @"lettuce"];
        NSPredicate *predicate = [NSPredicate predicateWithFormat:@" self.name  in %@", haveIngArray];
        NSArray *filteredArray = [recipeIngredientsArray filteredArrayUsingPredicate:predicate];
        for (RecipeIngredient *ing in filteredArray) {
            NSLog(@"%@", ing);
        }
    }
    return 0;
}

---

输出：

1 spoon rice
150 gr chicken

---

例如，知道食谱中没有或冰箱中没有什么：

NSArray *recipeIngredientsArray = @[
                                    ({
                                        RecipeIngredient *ing = [[RecipeIngredient alloc] init];
                                        ing.amount = @(1);
                                        ing.name = @"rice";
                                        ing.unit = @"spoon";
                                        ing;
                                    }),
                                    ({
                                        RecipeIngredient *ing = [[RecipeIngredient alloc] init];
                                        ing.amount = @(150);
                                        ing.name = @"chicken";
                                        ing.unit = @"gr";
                                        ing;
                                    }),
                                    ({
                                        RecipeIngredient *ing = [[RecipeIngredient alloc] init];
                                        ing.amount = @(1);
                                        ing.name = @"milk";
                                        ing.unit = @"cup";
                                        ing;
                                    }),
                                    ];
NSArray *haveIngArray = @[@"rice", @"chicken", @"lettuce"];
NSPredicate *predicate = [NSPredicate predicateWithFormat:@"not (self.name  in %@)", haveIngArray];
NSArray *filteredArray = [recipeIngredientsArray filteredArrayUsingPredicate:predicate];
NSArray *filteredIngNames = [filteredArray valueForKey:@"name"];
NSLog(@"in recipe but not in fridge: %@", filteredIngNames);
predicate = [NSPredicate predicateWithFormat:@"not (self  in %@.name)", recipeIngredientsArray];
filteredArray = [haveIngArray filteredArrayUsingPredicate:predicate];
NSLog(@"in fridge but not in recipe: %@", filteredArray);

---

输出：

in recipe but not in fridge: (
    milk
)
in fridge but not in recipe: (
    lettuce
)

---

如何从字符串中创建自定义成分对象：

NSNumberFormatter * f = [[NSNumberFormatter alloc] init];
[f setNumberStyle:NSNumberFormatterDecimalStyle];
NSArray *recipe = @[@"1 spoon of rice", @"150 gr chicken", @"1 cup of milk"];
NSMutableArray *recipeIngredientsArray = [@[] mutableCopy];
for (NSString *string in recipe) {
    NSArray *a = [string componentsSeparatedByString:@" "];
    RecipeIngredient *ing = [[RecipeIngredient alloc] init];
    ing.amount = [f numberFromString:a[0]];
    ing.name = [a lastObject];
    ing.unit = [[a subarrayWithRange:NSMakeRange(1, [a count]-2)] componentsJoinedByString:@" "];
    [recipeIngredientsArray addObject:ing];
}

记录recipeIngredientsArray打印

(
    1 spoon of rice,
    150 gr chicken,
    1 cup of milk,
)