How to slice from an array of objects in js?

Question

I have an array of objects like this:

const books =[ 
{id: "1", name: "twilight", category: "Movies", price: 10}, 
{id: "2", name: "jaws", category: "Movies", price: 22}, 
{id: "3", name: "the shining", category: "Movies", price: 1},
{id: "4", name: "beers", category: "Movies", price: 10}, 
{id: "5", name: "apples", category: "Movies", price: 22}, 
{id: "6", name: "mono", category: "Movies", price: 1}
]

Trying to slice the first 2, then second 2 etc.

How can I slice by 2 books at the time?

Answer 1

Array.prototype.slice()

The slice() method returns a shallow copy of a portion of an array into a new array object selected from begin to end (end not included). The original array will not be modified.

Try with for loop with a increment of 2 in each iteration. Pass the current value of i as the start position and i+2 as the end position as the method parameter:

const books =[ 
  {id: "1", name: "twilight", category: "Movies", price: 10}, 
  {id: "2", name: "jaws", category: "Movies", price: 22}, 
  {id: "3", name: "the shining", category: "Movies", price: 1},
  {id: "4", name: "beers", category: "Movies", price: 10}, 
  {id: "5", name: "apples", category: "Movies", price: 22}, 
  {id: "6", name: "mono", category: "Movies", price: 1}
]

for(var i=0; i<books.length; i+=2){
  var sliced = books.slice(i, i+2);
  console.log(sliced);
}

Answer 2

You can use the slice function passing the number of books to slice (i.e. 2):

let slicedBooks = []
for(var i = 0;i < books.length;i+= 2){
    let part_slice = books.slice(i, 2 + i);
    slicedBooks.push(part_slice);
    console.log(part_slice);
}
console.log(slicedBooks);

Be careful slice does not update books array, but returns a new array.