I have a categories array:
{id: 1, catName: "test", subCategories: Array(2)}
I need to retrieve the subCategories array based on the id of the category.
This return the entire category object, how can I change it to only return the subCategories array?
const subCategories = categoriesWithSub.filter(category => {
return category.id === departments.catId;
});
Destructure a find call:
const { subCategories } = categoriesWithSub.find(({ id }) => id === departments.catId);
Use Array#find to get the object and get the array using dot notation or bracket notation.
const subCategories = (categoriesWithSub.find(category => {
return category.id === departments.catId;
}) || {}).subCategories; // if find returns undefined then use an empty object to avoid error, alternately you can use if condition
You can use reduce.
const subCategories = categoriesWithSub.reduce((acc, category) => {
if (category.id === departments.catId) {
return acc.concat(category. subCategories)
}
return acc;
}, []);
Side note, reduce is a really powerful tool. find, map, forEach, filter are like shorthand versions of reduce for specific tasks.
Try this:
let categories = [ {id: 1, catName: "test", subCategories: ["test1","test2"]}, {id: 2, catName: "test", subCategories: Array(2)} ]
let departments = { catId: 1 }
const subCategories = categories.find(category => {
return category.id === departments.catId;
}).subCategories;
console.log( subCategories );
filter will return an array, subCategories will therefor be undefined. [0].subCategories; Would do the trick, but you'd need to be sure that filter always yields results.Try this
function getSubCategory() {
var categoriesWithSub = [{ id: 1, catName: "test", subCategories: ["test1","test2"] }, { id: 2, catName: "test", subCategories: ["test1","test2"] }]
var catId = 1;
for (var category = 0; category < categoriesWithSub.length; category++) {
if (categoriesWithSub[category].id == catId)
return categoriesWithSub[category].subCategories;
}
}
