JavaScript split: Preserve Empty Fields and Understand the Limit

The task

Inspect a simple pipe-delimited row whose second and final fields are empty. This format deliberately has no quoted separators or escaped field rules.

Runnable Node 22 example

const assert = require('node:assert/strict');

const row = 'north||7|';
const fields = row.split('|');
assert.deepEqual(fields, ['north', '', '7', '']);
assert.deepEqual(row.split('|', 2), ['north', '']);
assert.deepEqual('solo'.split('|'), ['solo']);
assert.deepEqual(''.split('|'), ['']);
assert.deepEqual(row.split('|', 0), []);
console.log(JSON.stringify(fields));

Expected output and explanation

The two neighboring pipes leave an empty second field, and the trailing pipe leaves an empty final field. Keeping those positions can matter when columns have meaning. Removing all falsy strings would silently shift later fields into earlier columns.

The two-element limit returns north and the next empty field. It discards the rest of this result rather than returning “7|” as a combined tail. With no matching separator, the entire input becomes one element; an empty source with this separator also produces one empty element.

Pitfall to check

A plain split is not a complete CSV parser. If separators may appear inside quoted fields, define and implement that format or use an appropriate existing parser. This small record’s behavior should not be generalized to every imported file.