---
type: "fhirpath-operator"
title: "FHIRPath Operator: in (in)"
operator: "in"
category: "Collections"
section: "6.4.2"
source: "fhirpath/operations.json"
---
# FHIRPath Operator: in (in)
If the left operand is a collection with a single item, this operator returns `true` if the item is in the right operand using equality semantics. If the left-hand side of the operator is empty, the result is empty, if the right-hand side is empty, the result is `false`. If the left operand has multiple items, an exception is thrown.

The following example returns `true` if `'Joe'` is in the list of given names for the Patient:

``` fhirpath
'Joe' in Patient.name.given
```
## Summary
- **Category**: Collections
- **Section**: `6.4.2`
- **Left Argument**: `Any`
- **Right Argument**: `collection`
- **Return Type**: `Boolean`
- **Empty Input Result**: `empty`
- **Errors on Multiple Input**: `true`
## Description
Returns `true` if the item in the left operand (single item collection) is in the right operand using equality semantics. If the left-hand side is empty, the result is empty; if the right-hand side is empty, the result is `false`. Throws an exception if the left operand has multiple items.
## Type Mapping
- `Any-collection`