group by in array using nested array's object field value javascript-CodePudding

I have an array like this

data = [
  { name : "sa", attributes : [{skin : "green"},{nose:"good"}]},
  { name : "sa", attributes : [{skin : "red"},{nose:"bad"}]},
  { name : "sa", attributes : [{skin : "green"},{nose:"good"}]},
  { name : "sa", attributes : [{nose:"good}]},
]

so i want the grouping of array based on skin attribute. I am using _ underscore library like this

const attributeType = "skin";
const groupedCollections = _.groupBy(colls, (col) => {
  const data = col.attributes.find((attribute) => {
    const keys = Object.keys(attribute);
    return keys.indexOf(attributeType) > -1 ? true : false
  });
  return data?.value
});

but this is making grouping under undefined.

Any help?

CodePudding user response：

You need to return the value of the wanted property.

const
    colls = [{ name: "sa", attributes: [{ skin: "green" }, { nose: "good" }] }, { name: "sa", attributes: [{ skin: "red" }, { nose: "bad" }] }, { name: "sa", attributes: [{ skin: "green" }, { nose: "good" }] }, { name: "sa", attributes: [{ nose: "good" }] }],
    attributeType = "skin",
    groupedCollections = _.groupBy(colls, ({ attributes }) =>  attributes
        .find(attribute => attributeType in attribute)
        ?.[attributeType]
    );

console.log(groupedCollections);

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