---
type: "fhirpath-functions"
title: "FHIRPath Functions"
source: "fhirpath/functions.json"
---
# FHIRPath Functions

- [Introduction](/fhirpath-intro)
- [Operations](/fhirpath-operations)

## Existence
- section: `5.1`
- [empty()](/fhirpath-fn-empty) - `5.1.1`
- [exists()](/fhirpath-fn-exists) - `5.1.2`
- [all()](/fhirpath-fn-all) - `5.1.3`
- [allTrue()](/fhirpath-fn-alltrue) - `5.1.4`
- [anyTrue()](/fhirpath-fn-anytrue) - `5.1.5`
- [allFalse()](/fhirpath-fn-allfalse) - `5.1.6`
- [anyFalse()](/fhirpath-fn-anyfalse) - `5.1.7`
- [subsetOf()](/fhirpath-fn-subsetof) - `5.1.8`
- [supersetOf()](/fhirpath-fn-supersetof) - `5.1.9`
- [count()](/fhirpath-fn-count) - `5.1.10`
- [distinct()](/fhirpath-fn-distinct) - `5.1.11`
- [isDistinct()](/fhirpath-fn-isdistinct) - `5.1.12`

## Filtering and projection
- section: `5.2`
- [where()](/fhirpath-fn-where) - `5.2.1`
- [select()](/fhirpath-fn-select) - `5.2.2`
- [sort()](/fhirpath-fn-sort) - `5.2.4`
- [repeat()](/fhirpath-fn-repeat) - `5.2.5`
- [repeatAll()](/fhirpath-fn-repeatall) - `5.2.6`
- [ofType()](/fhirpath-fn-oftype) - `5.2.7`
- [coalesce()](/fhirpath-fn-coalesce) - `5.2.8`

## Subsetting
- section: `5.3`
- [single()](/fhirpath-fn-single) - `5.3.2`
- [first()](/fhirpath-fn-first) - `5.3.3`
- [last()](/fhirpath-fn-last) - `5.3.4`
- [tail()](/fhirpath-fn-tail) - `5.3.5`
- [skip()](/fhirpath-fn-skip) - `5.3.6`
- [take()](/fhirpath-fn-take) - `5.3.7`
- [intersect()](/fhirpath-fn-intersect) - `5.3.8`
- [exclude()](/fhirpath-fn-exclude) - `5.3.9`

## Combining
- section: `5.4`
- [union()](/fhirpath-fn-union) - `5.4.1`
- [combine()](/fhirpath-fn-combine) - `5.4.2`

## Conversion
- section: `5.5`
- [iif()](/fhirpath-fn-iif) - `5.5.1`
- [toBoolean()](/fhirpath-fn-toboolean) - `5.5.2.1`
- [convertsToBoolean()](/fhirpath-fn-convertstoboolean) - `5.5.2.2`
- [toInteger()](/fhirpath-fn-tointeger) - `5.5.3.1`
- [convertsToInteger()](/fhirpath-fn-convertstointeger) - `5.5.3.2`
- [toLong()](/fhirpath-fn-tolong) - `5.5.3.3`
- [convertsToLong()](/fhirpath-fn-convertstolong) - `5.5.3.4`
- [toDate()](/fhirpath-fn-todate) - `5.5.4.2`
- [convertsToDate()](/fhirpath-fn-convertstodate) - `5.5.4.3`
- [toDateTime()](/fhirpath-fn-todatetime) - `5.5.5.1`
- [convertsToDateTime()](/fhirpath-fn-convertstodatetime) - `5.5.5.2`
- [toDecimal()](/fhirpath-fn-todecimal) - `5.5.6.1`
- [convertsToDecimal()](/fhirpath-fn-convertstodecimal) - `5.5.6.2`
- [toQuantity()](/fhirpath-fn-toquantity) - `5.5.7.1`
- [convertsToQuantity()](/fhirpath-fn-convertstoquantity) - `5.5.7.2`
- [toString()](/fhirpath-fn-tostring) - `5.5.8.1`
- [convertsToString()](/fhirpath-fn-convertstostring) - `5.5.8.2`
- [toTime()](/fhirpath-fn-totime) - `5.5.9.1`
- [convertsToTime()](/fhirpath-fn-convertstotime) - `5.5.9.2`

## String Manipulation
- section: `5.6`
- [indexOf()](/fhirpath-fn-indexof) - `5.6.1`
- [lastIndexOf()](/fhirpath-fn-lastindexof) - `5.6.2`
- [substring()](/fhirpath-fn-substring) - `5.6.3`
- [startsWith()](/fhirpath-fn-startswith) - `5.6.4`
- [endsWith()](/fhirpath-fn-endswith) - `5.6.5`
- [contains()](/fhirpath-fn-contains) - `5.6.6`
- [upper()](/fhirpath-fn-upper) - `5.6.7`
- [lower()](/fhirpath-fn-lower) - `5.6.8`
- [replace()](/fhirpath-fn-replace) - `5.6.9`
- [matches()](/fhirpath-fn-matches) - `5.6.10`
- [matchesFull()](/fhirpath-fn-matchesfull) - `5.6.11`
- [replaceMatches()](/fhirpath-fn-replacematches) - `5.6.12`
- [length()](/fhirpath-fn-length) - `5.6.13`
- [toChars()](/fhirpath-fn-tochars) - `5.6.14`

## Additional String Functions
- section: `5.7`
- [encode()](/fhirpath-fn-encode) - `5.7.1`
- [decode()](/fhirpath-fn-decode) - `5.7.2`
- [escape()](/fhirpath-fn-escape) - `5.7.3`
- [unescape()](/fhirpath-fn-unescape) - `5.7.4`
- [trim()](/fhirpath-fn-trim) - `5.7.5`
- [split()](/fhirpath-fn-split) - `5.7.6`
- [join()](/fhirpath-fn-join) - `5.7.7`

## Math
- section: `5.8`
- [abs()](/fhirpath-fn-abs) - `5.8.1`
- [ceiling()](/fhirpath-fn-ceiling) - `5.8.2`
- [exp()](/fhirpath-fn-exp) - `5.8.3`
- [floor()](/fhirpath-fn-floor) - `5.8.4`
- [ln()](/fhirpath-fn-ln) - `5.8.5`
- [log()](/fhirpath-fn-log) - `5.8.6`
- [power()](/fhirpath-fn-power) - `5.8.7`
- [round()](/fhirpath-fn-round) - `5.8.8`
- [sqrt()](/fhirpath-fn-sqrt) - `5.8.9`
- [truncate()](/fhirpath-fn-truncate) - `5.8.10`

## Tree navigation
- section: `5.9`
- [children()](/fhirpath-fn-children) - `5.9.1`
- [descendants()](/fhirpath-fn-descendants) - `5.9.2`

## Utility functions
- section: `5.10`
- [trace()](/fhirpath-fn-trace) - `5.10.1`
- [pathname()](/fhirpath-fn-pathname) - `5.10.2`
- [now()](/fhirpath-fn-now) - `5.10.3.1`
- [timeOfDay()](/fhirpath-fn-timeofday) - `5.10.3.2`
- [today()](/fhirpath-fn-today) - `5.10.3.3`
- [defineVariable()](/fhirpath-fn-definevariable) - `5.10.4`
- [lowBoundary()](/fhirpath-fn-lowboundary) - `5.10.5`
- [highBoundary()](/fhirpath-fn-highboundary) - `5.10.6`
- [precision()](/fhirpath-fn-precision) - `5.10.7`
- [yearOf()](/fhirpath-fn-yearof) - `5.10.8.1`
- [monthOf()](/fhirpath-fn-monthof) - `5.10.8.2`
- [dayOf()](/fhirpath-fn-dayof) - `5.10.8.3`
- [hourOf()](/fhirpath-fn-hourof) - `5.10.8.4`
- [minuteOf()](/fhirpath-fn-minuteof) - `5.10.8.5`
- [secondOf()](/fhirpath-fn-secondof) - `5.10.8.6`
- [millisecondOf()](/fhirpath-fn-millisecondof) - `5.10.8.7`
- [timezoneOffsetOf()](/fhirpath-fn-timezoneoffsetof) - `5.10.8.8`
- [dateOf()](/fhirpath-fn-dateof) - `5.10.8.9`
- [timeOf()](/fhirpath-fn-timeof) - `5.10.8.10`

## Date and Time Interval Functions
- section: `5.11`
- [duration()](/fhirpath-fn-duration) - `5.11.1`
- [difference()](/fhirpath-fn-difference) - `5.11.2`

## Comparison
- section: `6.2`
- [comparable()](/fhirpath-fn-comparable) - `6.2.5`

## Types
- section: `6.3`
- [is()](/fhirpath-fn-is) - `6.3.2`
- [as()](/fhirpath-fn-as) - `6.3.4`

## Boolean Logic
- section: `6.5`
- [not()](/fhirpath-fn-not) - `6.5.3`

## Aggregates
- section: `7`
- [aggregate()](/fhirpath-fn-aggregate) - `7.1`
- [sum()](/fhirpath-fn-sum) - `7.2`
- [min()](/fhirpath-fn-min) - `7.3`
- [max()](/fhirpath-fn-max) - `7.4`
- [avg()](/fhirpath-fn-avg) - `7.5`

## Reflection
- section: `10.2`
- [type()](/fhirpath-fn-type) - `10.2.2`