let category = "design" //This place is changing, like art, design, photo

let filtered = data.filter((item) => category === item.category_name)`

category contains a string. item.category_name is an array.

What I want to do is a filtering event. but an item can have multiple categories.

For example, the category of the 3rd item is as follows :

"category_name" : [ "design", "art" ],

How can I get the 3rd item to be selected when the category variable is art or design?

how can i compare array with a string

>Solution :

You can use the include method, it works for strings and arrays.

let filtered = data.filter((item) => item.category_name.includes(category))

so "design".includes("design") and ["design", "art"].includes("design") will both return true

However, it would be best if you turned item.categoryName into an array, for consistency. Items with one category could have an array with only one item.