javaScript filter nested objects and arrays

问题

My use case is something like this.

I have an array that has an object.
That each object has an array called menu
Again that menu array has objected.
That each object has an array dish_has_categories
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.

回答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)

回答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)

回答3:

You can use javascript filter() and some() . some() method checks if any of the elements in an array pass the function.

let data2 = data.filter(element => {
    let menu = element.menu.some(({dish_has_categories}) => dish_has_categories.some(({CategoryId}) => CategoryId === '8'));
    return menu;
           });
    console.log(data2);

来源：https://stackoverflow.com/questions/56371728/javascript-filter-nested-objects-and-arrays

标签

javascript

arrays

javascript-objects