Flatten array. This array can have multiple types: {}, [], "", undefined, null, 123 are all valid types inside the array.

Question

james · Accepted Answer

Bao Phan · Answer

A non-recursive approach:

const flatten = (a) => {
	a = a.reverse();
  const res = [];
  
  while (a.length > 0) {
  	const cur = a.pop();
    if (Array.isArray(cur)) {
    	for (let i = cur.length - 1; i >= 0; --i)
      	a.push(cur[i]);
    } else {
    	res.push(cur);
    }
  }
  
  return res;
}

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