I have this array in JS

initialArray = [A,B,C,C,D,E,F,F,G,K]

I want to split into:

chucks = [[A,B,C], [C,D,E,F], [F,G,K]]

Duplicate items are separators such as 'C' or 'F'

How to do this split in ES6?

CodePudding user response：

You could reduce the array and add either the value or a new array, depending on the last value.

const
    array = ['A','B','C','C','D','E','F','F','G','K'],
    result = array.reduce((r, v, i, { [i - 1]: last }) => {
        if (v === last) r.push([]);
        else r[r.length - 1].push(v);
        return r;
    }, [[]]);

console.log(result);

<iframe name="sif1" sandbox="allow-forms allow-modals allow-scripts" frameborder="0"></iframe>

CodePudding user response：

Does this works for you?

const initialArray = ["A","B","C","C","D","E","F","F","G","K"];
const chunks = [];

for (let i = 0; i < initialArray.length; i  = 3){
  const chunk = [];
  
  for (let x = i; x < i   3 && x < initialArray.length; x  ){
    chunk.push(initialArray[x]);
  }
  
  chunks.push(chunk);
}

console.log(chunks);

<iframe name="sif2" sandbox="allow-forms allow-modals allow-scripts" frameborder="0"></iframe>

CodePudding user response：

Fairly straight forward solution using a single for loop and holding the current chunk in a variable to push to.

const initialArray = ['A', 'A', 'B', 'C', 'C', 'D', 'E', 'F', 'F', 'G', 'K', 'K'];

const chunk_at_duplicate = (arr) => {
  let chunk = [], res = [chunk];

  for (let i = 0; i < arr.length; i  ) {
    if (arr[i] === arr[i - 1]) {
      res.push(chunk = []);
    }

    chunk.push(arr[i]);
  }

  return res;
};

console.log(chunk_at_duplicate(initialArray));

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