jquery split array with last element of a chunk being first element of the next chunk

Question

I want to split an array in jquery so that after splitting, the last element for previous array should be the first element of current array.

var arr = [1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16];

If I do splice then it will splice exactly same size and next array will be next element. so if I am splicing it into 5 my output should be

var firstArr = arr.splice[0,4];
var secondArr = arr.splice[0,4];
var thirdArr = arr.splice[0,4];
var fourthArr = arr.splice[0,4];
var fifthArr = arr.splice[0,4];

Right now I am getting

[1,2,3,4]
[5,6,7,8]
...

What I need is

//firstArr = [1,2,3,4];
//secondArr = [4,5,6,7];
//thirdArr = [7,8,9,10];
//fourthArr = [10,11,12,13];
//fifthArr = [13,14,15,16];

How to achieve this in jQuery ?

Robin Mackenzie · Accepted Answer · 2021-06-28 11:55:37Z

I don't know a jquery array function that is preferable to using a plain javascript solution. Below is an example that generically handles your requirement by:

taking the number of chunks as the ceil of: the length of input array plus the floor number of duplicated entries, all divided by the size of the output chunk
uses slice such that the last element for previous array is the first element of current array.

// chunking function
function chunk(arr, size) {
  if (size === 0) return [];
  var arrCount = Math.ceil((arr.length + Math.floor(arr.length / size)) / size);
  var chunks = [];
  for (let i=0; i<arrCount; ++i) {
    chunks.push(arr.slice(i * (size - 1), i * (size - 1) + size));
  }
  return chunks;
}

// tests
console.log(chunk([1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16], 4));
console.log(chunk([1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16], 7));
console.log(chunk([1,2,3,4,5,6,7,8,9], 3));
console.log(chunk([1,2,3,4,5,6,7,8,9,10], 3));
console.log(chunk([1,2,3], 8));
console.log(chunk([], 10));
console.log(chunk([1, 2, 3, 4], 0));
console.log(chunk(['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i'], 4));

.as-console-wrapper { max-height: 100% !important; top: 0; }

Dharman · Accepted Answer · 2021-06-28 11:40:51Z

0

const arr = [1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16]

let slices = []

let start = 0
let end = 3
for(i = 0; i < 5; i++){
    let slice = arr.slice(start,end)
    slice.push(arr[end])
    start += 3
    end += 3
    slices.push(slice)
}

edited Jun 28, 2021 at 11:40

Dharman♦

33.9k27 gold badges103 silver badges156 bronze badges

answered Jun 28, 2021 at 11:35

devil1321

196 bronze badges

Comments

Exodus 4D · Accepted Answer · 2024-09-26 03:22:24Z

const chunk = (a1, s) => {
  const a2 = [];
  let i = k = j = 0;
  while (s > 1 && a1[i - k]) {
    j = i % s;
    k = (i - j) / s
    a2[k] ??= [];
    a2[k][j] = a1[i - k];
    i++;
  }
  return a2;
}



console.log(chunk([1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16], 4));
console.log(chunk([1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16], 7));
console.log(chunk([1, 2, 3, 4, 5, 6, 7, 8, 9], 3));
console.log(chunk([1, 2, 3, 4, 5, 6, 7, 8, 9, 10], 3));
console.log(chunk([1, 2, 3], 8));
console.log(chunk([], 10));
console.log(chunk([1, 2, 3, 4], 0));
console.log(chunk(['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i'], 4));

Collectives™ on Stack Overflow

jquery split array with last element of a chunk being first element of the next chunk

3 Answers 3

Comments

Comments

Comments

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

Comments

Comments

Comments

Related