30-seconds-of-code/snippets/js/s/initialize-array-with-range.md

title, type, language, tags, cover, excerpt, dateModified

title	type	language	tags	cover	excerpt	dateModified
Initialize array with range	snippet	javascript	array	spanish-resort	Initializes an inclusive array with numbers in a range, using a common `step` difference.	2020-10-22T20:23:47+03:00

Initializes an array containing the numbers in the specified range where start and end are inclusive with their common difference step.

• Use Array.from() to create an array of the desired length.
• Use (end - start + 1) / step and a map function to fill the array with the desired values in the given range.
• Omit the second argument, start, to use a default value of 0.
• Omit the last argument, step, to use a default value of 1.

const initializeArrayWithRange = (end, start = 0, step = 1) =>
  Array.from(
    { length: Math.ceil((end - start + 1) / step) },
    (_, i) => i * step + start
  );

initializeArrayWithRange(5); // [0, 1, 2, 3, 4, 5]
initializeArrayWithRange(7, 3); // [3, 4, 5, 6, 7]
initializeArrayWithRange(9, 0, 2); // [0, 2, 4, 6, 8]