Array Length
Enforce a minimum or maximum item count on array fields
Array Length
The arrayLength rule validates that an array field — for example from <FieldArray> or a checkbox group — has at least min items and at most max items. An empty array fails the rule even without an explicit min.
Configuration
| Config flag | Type | Description |
|---|---|---|
arrayLength | { min?: number, max?: number, message?: string } | Item count bounds. Omitting max applies the minimum only. |
validationSchema: {
tags: { arrayLength: { min: 1, max: 5 } },
}With a custom message:
tags: { arrayLength: { min: 1, max: 5, message: "Choose 1 to 5 tags" } }V builder
import { V } from "formify-js";
V.arrayLength(1, 5)
V.arrayLength(1) // minimum only
V.arrayLength(1, 5, "Choose 1 to 5 tags")Default message
The default message reflects your bounds, e.g. Must have at least 1 item or Must have at most 5 items.
Examples
| Value | Rule | Result |
|---|---|---|
[] | { min: 1, max: 5 } | ❌ Invalid (empty) |
["a"] | { min: 1, max: 5 } | ✅ Valid |
["a", "b", "c", "d", "e", "f"] | { min: 1, max: 5 } | ❌ Invalid |
Things to know
- Both bounds are inclusive.
- An empty array fails even when only
maxis set — combine with per-item validation inside<FieldArray>for full control over each entry.