---
type: "fhirpath-function"
title: "FHIRPath Function: toLong"
function: "toLong"
category: "Conversion"
section: "5.5.3.3"
source: "fhirpath/functions.json"
---
# FHIRPath Function: toLong
_No canonical section match found in index.md._
## Summary
- **Category**: Conversion
- **Section**: `5.5.3.3`
- **Return Type**: `Long`
- **Empty Input Result**: `empty`
- **Errors on Multiple Input**: `true`
## Description
If the input collection contains a single item, this function will return a single Long if the item is an Integer or Long, a String convertible to a 64 bit integer, or a Boolean.
## Arguments
- none
## Type Mapping
- `Boolean-Long`
- `Integer-Long`
- `Long-Long`
- `String-Long`
## Example
```fhirpath
'123'.toLong() // returns 123L
true.toLong() // returns 1L
```