# Generate a hash of a string

Compute the 32-bit hash Java’s String.hashCode uses.

Canonical: https://1loc.dev/string/generate-a-hash-of-a-string/
Version: 1.0.0
Runtime: JavaScript · Node.js 22 / modern browsers
Verification: Local fixtures; no external services
Updated: 2026-10-28

## Implementation

```javascript
function hashString(text) { return text.split('').reduce((hash, char) => (Math.imul(31, hash) + char.charCodeAt(0)) | 0, 0); }
```

## Input

```json
"hello"
```

## Expected output

```json
99162322
```

## Edge case

Input:
```json
""
```
Output:
```json
0
```

## Limits

- Not cryptographic and collision-prone: use it for bucketing, never for integrity. To authenticate data use HMAC-SHA256, as in the webhook signature lab.

The lab validates types and size before calling this function. Add equivalent validation at your own trust boundary.

## Source and license

Original: https://github.com/phuocng/1loc/blob/14b481cf60dff1620ab1bb99a43b1f68068cdd9b/contents/generate-a-hash-of-a-string.mdx
Author: Nguyen Huu Phuoc and original contributors
Contributors: See original repository history
Source commit: 14b481cf60dff1620ab1bb99a43b1f68068cdd9b
Copyright (c) 2020 phuoc-ng
License: MIT — https://1loc.dev/licenses/
Maintainer: Oveyon
Modifications: Keeps the Math.imul variant; documents that it is not cryptographic. Original MDX retained as inert source evidence.