How to get populate an array with numerical data for unit testing, math or array identifiers

In this next code snippet, we’ll show an example to populate an array with numerical data for unit testing, math or array identifiers.

const initializeArrayUntil = (conditionFn, mapFn) => {
  const arr = [];
  let i = 0;
  let el = undefined;
  do {
    el = mapFn(i, el, arr);
    arr.push(el);
    i++;
  } while (!conditionFn(i, el, arr));
  return arr;
};

initializeArrayUntil(
  (i, val) => val > 10,
  (i, val, arr) => (i <= 1 ? 1 : val + arr[i - 2])
); // [1, 1, 2, 3, 5, 8, 13]

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Tags: array, array population, array data, unit testing, fake data, math, array id, numerical data, array manipulation, function, method, javascript, js