# RangeError: Invalid array length

**Code:** `invalid array length` · **Category:** JavaScript · **Seen on:** JavaScript

An array was created or resized with a negative, fractional or enormous length.

## Meaning

new Array(n) with n negative/NaN, or array.length set to an invalid value. Often n comes from a failed calculation.

## Common causes

- new Array(-1) or new Array(NaN)
- Length from a bad calculation or input
- Infinite loop pushing until memory limits

## Quick fix

1. Validate n is a non-negative integer
2. Use Array.from({ length: n })

## Detailed fix by platform

### JavaScript

1. `const n = Math.max(0, Math.floor(count)
2. 0); const rows = Array.from({ length: n }, () => []);`

## How to diagnose

1. **Value** — What length was requested?
2. **Recent change** — Did it start after a deploy, upgrade, or configuration change? Compare with the last working version.

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Source: [WhatIsMyError](https://whatismyerror.com/errors/javascript/rangeerror-invalid-array-length)