> For the complete documentation index, see [llms.txt](https://radoslaw-medryk.gitbook.io/verifica/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://radoslaw-medryk.gitbook.io/verifica/predicates/built-in-predicates/isarrayof.md).

# isArrayOf

```typescript
isArrayOf(itemPredicate)
```

Verifies if provided `Validatable` represents an array where each item matches provided `itemPredicate`.

### Arguments:

* `itemPredicate` - required, of type `Predicate`

### Possible errors:

#### If provided `Validatable` is not an array:

```typescript
{
    type: "isArray",
    path: [/* ... */]
}
```

#### If provided `Validatable` is an array that contains some items not matching the `itemPredicate`:

Errors for all not matching items will be returned, as errors returned by `itemPredicate`. `path` property of each error will point to the element in the array that didn't match.

### Examples:

Each of examples uses this import statement:

```typescript
const { asVerificable, isValid, isArrayOf, isString, getErrors } = require("verifica");
```

#### Non-array values (like string in this example) are not a valid array, and will fail with an `isArray` error:

```typescript
const verificable = asVerificable("something");
isValid(verificable, isArrayOf(isString)); // false
getErrors(verificable, isArrayOf(isString)); // [{ type: "isArray", path: [] }]
```

#### Empty array satisfies any `itemPredicate`, since there are no array elements that doesn't match it:

```typescript
const verificable = asVerificable([]);
isValid(verificable, isArrayOf(isString)); // true
```

#### If some items in the array doesn't match `itemPredicate`, `isArrayOf` fails returning errors for all not-matching items. Errors are as returned by `itemPredicate`, including item index in the array in the `path` property:

```typescript
const verificable = asVerificable(["one", "two", null]);
isValid(verificable, isArrayOf(isString)); // false
getErrors(verificable, isArrayOf(isString)); // [{ type: "isString", path: [2] }]
```