Javascript - How to filter a nested array in array of object using filter and map?

GauthamMuralidharan
January 19, 2024
245 views
3 votes
3 Answers

I want to filter the below array:

let data = [
    {
        title : "fashion",
            options : [{
                title : "men",
                options : [
                    { title : "shirt"},
                    { title : "pants"},
                    { title : "belt"},
                    { title : "shoes"},
                ]
            },{
                title : "women",
                options : [
                    { title : "shirt"},
                    { title : "jeans"},
                    { title : "sarees"},
                    { title : "salwar"},
                ]
            }
        ]
    },
    {
        title : "electronics",
            options : [{
                title : "mobile",
                options : [
                    { title : "Samsung"},
                    { title : "Nokia"},
                    { title : "Apple"},
                    { title : "OnePlus"},
                ]
            },{
                title : "TV",
                options : [
                    { title : "Samsung"},
                    { title : "Sony"},
                    { title : "Sansui"},
                    { title : "OnePlus"},
                ]
            }
        ]
    }
]

I want to filter the options array in the seond level nesting. For example, I want to filter and find out the Samsung options alone and get the below output:

let data = [
        {
            title : "electronics",
                options : [{
                    title : "mobile",
                    options : [
                        { title : "Samsung"}                            
                    ]
                },{
                    title : "TV",
                    options : [
                        { title : "Samsung"},
                    ]
                }
            ]
        }
    ]

I am able to achieve the same using three nested for loop. Is there a better way to do this using filter and map?

Tags: javascript

Answers

You can use the following approach, it uses the map and the filter function to filter the array.
Let me know if this solves your problem

let searchTerm = "Samsung";

let filteredData = data.map(category => {
  let filteredOptions = category.options.map(subCategory => {
    let filteredItems = subCategory.options.filter(item => item.title === searchTerm);
    if (filteredItems.length > 0) {
      return {
        title: subCategory.title,
        options: filteredItems
      };
    }
    return null;
  }).filter(Boolean); // Remove null entries

  if (filteredOptions.length > 0) {
    return {
      title: category.title,
      options: filteredOptions
    };
  }
  return null;
}).filter(Boolean); // Remove null entries

console.log(filteredData)

<script>
  let data = [{
      title: "fashion",
      options: [{
        title: "men",
        options: [{
            title: "shirt"
          },
          {
            title: "pants"
          },
          {
            title: "belt"
          },
          {
            title: "shoes"
          },
        ]
      }, {
        title: "women",
        options: [{
            title: "shirt"
          },
          {
            title: "jeans"
          },
          {
            title: "sarees"
          },
          {
            title: "salwar"
          },
        ]
      }]
    },
    {
      title: "electronics",
      options: [{
        title: "mobile",
        options: [{
            title: "Samsung"
          },
          {
            title: "Nokia"
          },
          {
            title: "Apple"
          },
          {
            title: "OnePlus"
          },
        ]
      }, {
        title: "TV",
        options: [{
            title: "Samsung"
          },
          {
            title: "Sony"
          },
          {
            title: "Sansui"
          },
          {
            title: "OnePlus"
          },
        ]
      }]
    }
  ]
</script>

To achieve a good performance you 2 nested Array::reduce() to avoid intermediate arrays:

const result = data.reduce((r, item) => {
  const options = item.options.reduce((r, item) => {
    const options = item.options.filter(item => item.title === 'Samsung');
    if(options.length){
      r.push({title: item.title, options});
    }
    return r;
  }, []);
  if(options.length){
    r.push({title: item.title, options});
  }
  return r;
}, []);

console.log(JSON.stringify(result, null, 4));

<script>
let data=[{title:"fashion",options:[{title:"men",options:[{title:"shirt"},{title:"pants"},{title:"belt"},{title:"shoes"},]},{title:"women",options:[{title:"shirt"},{title:"jeans"},{title:"sarees"},{title:"salwar"},]}]},{title:"electronics",options:[{title:"mobile",options:[{title:"Samsung"},{title:"Nokia"},{title:"Apple"},{title:"OnePlus"},]},{title:"TV",options:[{title:"Samsung"},{title:"Sony"},{title:"Sansui"},{title:"OnePlus"},]}]}];
</script>

` Chrome/120
---------------------------------------------------------
Alexander   1.00x  |  x10000000  632  640  643  649   773
Julius      1.37x  |  x10000000  867  880  892  984  1020
---------------------------------------------------------
https://github.com/silentmantra/benchmark `

let data=[{title:"fashion",options:[{title:"men",options:[{title:"shirt"},{title:"pants"},{title:"belt"},{title:"shoes"},]},{title:"women",options:[{title:"shirt"},{title:"jeans"},{title:"sarees"},{title:"salwar"},]}]},{title:"electronics",options:[{title:"mobile",options:[{title:"Samsung"},{title:"Nokia"},{title:"Apple"},{title:"OnePlus"},]},{title:"TV",options:[{title:"Samsung"},{title:"Sony"},{title:"Sansui"},{title:"OnePlus"},]}]}];

// @benchmark Julius

let searchTerm = "Samsung";

data.map(category => {
  let filteredOptions = category.options.map(subCategory => {
    let filteredItems = subCategory.options.filter(item => item.title === searchTerm);
    if (filteredItems.length > 0) {
      return {
        title: subCategory.title,
        options: filteredItems
      };
    }
    return null;
  }).filter(Boolean); // Remove null entries

  if (filteredOptions.length > 0) {
    return {
      title: category.title,
      options: filteredOptions
    };
  }
  return null;
}).filter(Boolean);

// @benchmark Alexander

data.reduce((r, item) => {
  const options = item.options.reduce((r, item) => {
    const options = item.options.filter(item => item.title === 'Samsung');
    if(options.length){
      r.push({title: item.title, options});
    }
    return r;
  }, []);
  if(options.length){
    r.push({title: item.title, options});
  }
  return r;
}, []);


/*@end*/eval(atob('e2xldCBlPWRvY3VtZW50LmJvZHkucXVlcnlTZWxlY3Rvcigic2NyaXB0Iik7aWYoIWUubWF0Y2hlcygiW2JlbmNobWFya10iKSl7bGV0IHQ9ZG9jdW1lbnQuY3JlYXRlRWxlbWVudCgic2NyaXB0Iik7dC5zcmM9Imh0dHBzOi8vY2RuLmpzZGVsaXZyLm5ldC9naC9zaWxlbnRtYW50cmEvYmVuY2htYXJrL2xvYWRlci5qcyIsdC5kZWZlcj0hMCxkb2N1bWVudC5oZWFkLmFwcGVuZENoaWxkKHQpfX0='));

This should do the job

    const ans = (data
        .map(({ title, options }) => ({
            title,
            options: options
                .filter(({ options }) => options.some(({ title }) => title === "Samsung"))
                .filter(({options})=>options.length>0)
                .map(({ title, options }) => ({
                    title,
                    options: options.filter(({ title }) => title === "Samsung"),
                })),
        })).filter(({options})=>options.length>0)
    );

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Javascript – How to filter a nested array in array of object using filter and map?

Answers