javaScript filter nested objects and arrays

Question

My use case is something like this.

1. I have an array that has an object.
2. That each object has an array called menu
3. Again that menu array has objected.
4. That each object has an array dish_has_categories
5. In dish_has_categories array, if there is an object with CategoryId is equal to 8 I want to filter out that root object.

My original data object

const data = [{
        menuName: "Hot dogs",
        menu: [
            {
            dishId: '1',
            dish_has_categories: [{
                CategoryId: '8'
            }]
        },
         {
            dishId: '2',
            dish_has_categories: [{
                CategoryId: '9'
            }]
        }]
    },
    {
        menuName: "Burgers",
        menu: [{
            dishId: '3',
            dish_has_categories: [{
                CategoryId: '6'
            }]
        }, {
            dishId: '4',
            dish_has_categories: [{
                CategoryId: '4'
            }]
        }]
    },
    {
        name: "Drinks",
        menu: []
    }
]

My expect result is

[{
        menuName: "Hot dogs",
        menu: [
            {
            dishId: '1',
            dish_has_categories: [{
                CategoryId: '8'
            }]
        },
         {
            dishId: '2',
            dish_has_categories: [{
                CategoryId: '9'
            }]
        }]
    }]
    

what I've done up to now is

const data2 = data.filter(element => {
    return element.menu.length > 0
})

I have no idea how to deep filter inside nested objects and arrays. Hope my question is clear to you all.

Answer 1

You can use filter() with nested some().

The some() method tests whether at least one element in the array passes the test implemented by the provided function. It returns a Boolean value

const data = [{ menuName: "Hot dogs", menu: [ { dishId: '1', dish_has_categories: [{ CategoryId: '8' }] }, { dishId: '2', dish_has_categories: [{ CategoryId: '9' }] }] }, { menuName: "Burgers", menu: [{ dishId: '3', dish_has_categories: [{ CategoryId: '6' }] }, { dishId: '4', dish_has_categories: [{ CategoryId: '4' }] }] }, { name: "Drinks", menu: [] } ]

const res = data.filter(x => 
                x.menu.some(y => 
                    y.dish_has_categories.some(z => z.CategoryId === '8')
                )
            );
console.log(res)