Filter()

Given data:

const items = [
    { name: 'Bike',     price: 100  },
    { name: 'TV',       price: 200  },
    { name: 'Album',    price: 10   },
    { name: 'Book',     price: 5    },
    { name: 'Phone',    price: 500  },
    { name: 'Computer', price: 1000 },
    { name: 'Keyboard', price: 25   }
]

Filtering items

const filteredItems = items.filter((item) => {
    return item.price <= 100
})

console.log(filteredItems)

Result:

. (3) ["Video 1 Recorded", "Video 2 Recorded", "Video 3 Recorded"] 0: "Video 1 Recorded" 1: "Video 2 Recorded" 2: "Video 3 Recorded" length: 3 proto: Array(0)

Reading this like English,

• The immutable variable filteredItems receives the following value(s).
• The array of objects has the filter method applied
  • The filter uses an arrow function #2 that takes a single parameter (item)
  • The arrow function says "for each item in items, pass each item into my function body and operate upon it"
  • Inside the function body the items price attribute is operated on with basic arithmetic to determine if it meets the condition <=
  • If true, the data is returned with all other valid data that met the condition as the .filter method is an array method and likely returns an array as a result
  • Each item that met the condition is then added to the resulting returned array
• The returned array is then assigned to the constant variable filteredItems