## checkForNull() function

Recursively checks for null values in an object.

Note that "null" is a special value in JSON that is not allowed in FHIR.

**Signature:**

```typescript
export declare function checkForNull(value: unknown, path: string, issues: OperationOutcomeIssue[]): void;
```

## Parameters

| Parameter | Type | Description |
| --- | --- | --- |
| value | unknown | Input value of any type. |
| path | string | Path string to the value for OperationOutcome. |
| issues | OperationOutcomeIssue\[\] | Output list of issues. |

**Returns:**

void

- [checkForNull() function](/content/docs/sdk/core.checkfornull#checkfornull-function/index.html)
- [Parameters](/content/docs/sdk/core.checkfornull#parameters/index.html)