SOURCE

const books = [
  {name:'gitbook',category:'git'},
  {name:'reactbook',category:'react'},
  {name:'vuebook',category:'vue'},
  {name:'cssbook',category:'html&css'},
  {name:'htmlbook',category:'html&css'},
  ]
const is_html_css_books = item => item.category === 'html&css'
const is_git_books = item => item.category ==='git'
const html_css_books = books.filter(is_html_css_books)
const git_books = books.filter(is_git_books)
console.log(JSON.stringify(html_css_books))
console.log(JSON.stringify(git_books))