Filtering nested array of objects with some filters-CodePudding

I am trying to filter an array, based on some nested object. I prepared some Fiddle

Input array looks like this:

let arrayOfElements = 
    [
        {
           "name": "a",
           "subElements": 
           [
             {"surname": 1},
             {"surname": 2}
           ]
        },
        {
           "name": "b",
           "subElements": 
           [
             {"surname": 3},
             {"surname": 1}
           ]
        },
        {
           "name": "c",
           "subElements": 
           [
             {"surname": 2},
             {"surname": 5}
           ]
        }
    ];

I'm expecting this output , as I have similar data of management.

let filterArray= 
    [
        {
           "name": "a",
           "subElements": 
           [
             {"surname": 1}
           ]
        },


        {
           "name": "a",
           "subElements": 
           [
             {"surname": 2},
           ]
        },


        {
           "name": "b",
           "subElements": 
           [
             {"surname": 3}
           ]
        },


      {
           "name": "b",
           "subElements": 
           [
             {"surname": 1}
           ]
        },


        {
           "name": "c",
           "subElements": 
           [
             {"surname": 2}
           ]
        },


        {
           "name": "c",
           "subElements": 
           [
             {"surname": 5}
           ]
        }


    ];

CodePudding user response：

You can do that easily with a reduce:

let arrayOfElements = 
    [
        {
           "name": "a",
           "subElements": 
           [
             {"surname": 1},
             {"surname": 2}
           ]
        },
        {
           "name": "b",
           "subElements": 
           [
             {"surname": 3},
             {"surname": 1}
           ]
        },
        {
           "name": "c",
           "subElements": 
           [
             {"surname": 2},
             {"surname": 5}
           ]
        }
    ];
    
 const result = arrayOfElements.reduce((acc, el) => {
    for(let subElement of el.subElements){ //For each of the subelements
      acc.push({  //Create a new element only with its data
         name: el.name,
         subElements: [subElement]
      });
    }
    return acc;
 }, [])

console.log(result)

CodePudding user response：

You're looking for flatMap:

arrayOfElements.flatMap(elem =>
    elem.subElements.map(sub => (
        {...elem, subElements: [sub]}
    ))
)