---
type: "fhirpath-function"
title: "FHIRPath Function: toInteger"
function: "toInteger"
category: "Conversion"
section: "5.5.3.1"
source: "fhirpath/functions.json"
---
# FHIRPath Function: toInteger
_No canonical section match found in index.md._
## Summary
- **Category**: Conversion
- **Section**: `5.5.3.1`
- **Return Type**: `Integer`
- **Empty Input Result**: `empty`
- **Errors on Multiple Input**: `true`
## Description
If the input collection contains a single item, this function will return a single integer if the item is an Integer, a String convertible to an integer, or a Boolean.
## Arguments
- none
## Type Mapping
- `Boolean-Integer`
- `Integer-Integer`
- `String-Integer`
## Example
```fhirpath
'123'.toInteger() // returns 123
```