Showing value from NSArray on the basis of other NSArray

问题

(My english is not good).

I have two NSArray.

EXAMPLE: 1st NSArray is storing

NSArray category= { ID:1,Name:Category1;ID:2, Name: Category2;ID:3, Name:Category3;}

2nd NSArray is storing

 NSArray product= {cat_ID:1, Category-Name:Category1, product_ID:1, Name: Banana;
                cat_ID:1, Category-Name:Category1, product_ID:2, Name: apple;
                cat_ID:1, Category-Name:Category1, product_ID:3, Name: berry;
                cat_ID:2, Category-Name:Category2, product_ID:4, Name: cantaloupe;
                cat_ID:2, Category-Name:Category2, product_ID:5, Name: elderberry;
                cat_ID:2, Category-Name:Category2, product_ID:6, Name: ginger;
                cat_ID:2, Category-Name:Category2, product_ID:7, Name: watermelon;
                cat_ID:3, Category-Name:Category3, product_ID:8, Name: xigua;
                cat_ID:3, Category-Name:Category3, product_ID:9, Name: avocado;
                cat_ID:3, Category-Name:Category3, product_ID:10, Name: basil;
                cat_ID:3, Category-Name:Category3, product_ID:11, Name: alfalfa;
                cat_ID:3, Category-Name:Category3, product_ID:12, Name: blackcurrant;}

All i want is if category name (i mean 1st NSArray category.name) is equals to 2nd NSArray's category name (i mean product.Category-Name) then print all product name. Example: category.name== Category1; then result will be Product.Name = Banana, Apple, Berry;

How to do this?

回答1:

From your json-like notation, we will assume that key value pairs in "{...}" are NSDictionary objects. And you have an array of said NSDictionary objects, "[{...},{...},...]"

To get the products for a given category:

NSString *category = @"Category1";
NSArray *result = [NSArray array];
for (NSDictionary *dic in products) {
    if ([[dic objectForKey:@"Category-Name"] isEqualToString: category])
        result = [result arrayByAddingObject: [dic objectForKey: @"Name"] ];
}

回答2:

I would suggest you not to make Array for this kind of logic.

You should use NSDictionary/NSMutableDictionary.

Then you can filter easily by NSPredicateFilter.

回答3:

You can also do this task in compact way by using NSPredicate

NSString *selectedCategory = @"Category1";

//filter array by category using predicate
NSPredicate *predicate = [NSPredicate predicateWithFormat:@"Category-Name == %@", selectedCategory];

NSArray *filteredArray = [product filteredArrayUsingPredicate:predicate];

or just follow my blog rajneesh071.blogspot.in for more info

来源：https://stackoverflow.com/questions/13717735/showing-value-from-nsarray-on-the-basis-of-other-nsarray

标签

objective-c

nsarray