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.

Solution 1

You can use filter and some

Here nested some is used to check whether any of dish_has_categories has CategoryId equal to '8', if it is true then we include that menu in final output else we don't

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: [] } ]

let op = data.filter(val => {
  let menu = val.menu.some(({dish_has_categories}) => dish_has_categories.some(({CategoryId}) => CategoryId === '8'))
  return menu
})

console.log('filtered values -->\n',op)

let names = op.map(({menuName})=> menuName)

console.log('Names --> \n', names)

Solution 2

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)

Comments

[margherita pizza]

Thanks a lot. This works! If I want to push this menu name ("Hot dogs") to new separate array. Where do I can do that?

[Syed mohamed aladeen]

Hi, can you please explain, why you are using z.CategoryId === '8'? 8 is hardcoded here.

[margherita pizza]

Thanks a lot. This works! If I want to push this menu name ("Hot dogs") to new separate array. Where do I can do that?

[Code Maniac]

@PathumSamararathna you want to get names of filtered values or all the values ? you can simply use map and return name only from map

[Code Maniac]

@PathumSamararathna i have added example of getting names in new array too you can check :) always happy to help :)

[Maheer Ali]

@PathumSamararathna You can use map() for that I have updated.

[Maheer Ali]

@SyedMohamedAladeen Becasue OP asked )"In dish_has_categories array, if there is an object with CategoryId is equal to 8 I want to filter out that root object."_