Power Automate & Azure Logic Apps Expression Functions Reference

This document provides a complete reference for expression functions available in Azure Logic Apps and Power Automate workflow expressions.

Expression Syntax

•Functions in expressions: @{functionName(parameter)}
•Nested functions: @{outerFunction(innerFunction(parameter))}
•Property access: @{functionName(parameter).propertyName}
•Interpolated format (inline with text): text @{functionName(parameter)} text
•Parameters are evaluated left to right
•A ? after a parameter means it is optional

String Functions

Function	Signature	Description
chunk	`chunk('<text>', <length>)`	Split a string into chunks of equal length
concat	`concat('<text1>', '<text2>', ...)`	Combine two or more strings. Max result: 104,857,600 chars
endsWith	`endsWith('<text>', '<searchText>')`	Check if string ends with substring (case-insensitive)
formatNumber	`formatNumber(<number>, '<format>', '<locale>'?)`	Format a number as a string
guid	`guid('<format>'?)`	Generate a GUID. Formats: "N", "D" (default), "B", "P", "X"
indexOf	`indexOf('<text>', '<searchText>')`	Return starting position of substring (case-insensitive, 0-based). Returns -1 if not found
isFloat	`isFloat('<string>', '<locale>'?)`	Check if string is a floating-point number
isInt	`isInt('<string>')`	Check if string is an integer
lastIndexOf	`lastIndexOf('<text>', '<searchText>')`	Return position of last occurrence of substring (case-insensitive, 0-based)
length	`length('<collection>')`	Return number of items in string or array
nthIndexOf	`nthIndexOf('<text>', '<searchText>', <occurrence>)`	Return position of nth occurrence of substring. Negative occurrence searches from end
replace	`replace('<text>', '<oldText>', '<newText>')`	Replace substring (case-sensitive)
slice	`slice('<text>', <startIndex>, <endIndex>?)`	Return substring by start/end position. Supports negative indices
split	`split('<text>', '<delimiter>')`	Split string into array by delimiter
startsWith	`startsWith('<text>', '<searchText>')`	Check if string starts with substring (case-insensitive)
substring	`substring('<text>', <startIndex>, <length>?)`	Return characters from specified position (0-based). startIndex + length must be <= string length
toLower	`toLower('<text>')`	Convert to lowercase
toUpper	`toUpper('<text>')`	Convert to uppercase
trim	`trim('<text>')`	Remove leading and trailing whitespace

Collection Functions

Function	Signature	Description
chunk	`chunk([<collection>], <length>)`	Split array into chunks of equal length
contains	`contains('<collection>', '<value>')`	Check if collection has specific item (case-sensitive)
empty	`empty('<collection>')`	Check if collection is empty
first	`first('<collection>')`	Return first item
intersection	`intersection([<coll1>], [<coll2>], ...)`	Return only common items across collections
item	`item()`	Return current item in a repeating action over an array
join	`join([<collection>], '<delimiter>')`	Join array items with delimiter. Max result: 104,857,600 chars
last	`last('<collection>')`	Return last item
length	`length([<collection>])`	Return number of items
reverse	`reverse([<collection>])`	Reverse order of items
skip	`skip([<collection>], <count>)`	Remove items from front, return rest
sort	`sort([<collection>], '<sortBy>'?)`	Sort items. Optional key for object sorting
take	`take('<collection>', <count>)`	Return items from front
union	`union([<coll1>], [<coll2>], ...)`	Return all items from all collections (no duplicates)

Logical Comparison Functions

Note: null values are converted to empty string ("") in comparisons.

Function	Signature	Description
and	`and(<expr1>, <expr2>, ...)`	True if all expressions are true
equals	`equals(<object1>, <object2>)`	True if both values are equivalent
greater	`greater(<value>, <compareTo>)`	True if first > second
greaterOrEquals	`greaterOrEquals(<value>, <compareTo>)`	True if first >= second
if	`if(<expression>, <valueIfTrue>, <valueIfFalse>)`	Return value based on boolean expression
less	`less(<value>, <compareTo>)`	True if first < second
lessOrEquals	`lessOrEquals(<value>, <compareTo>)`	True if first <= second
not	`not(<expression>)`	True if expression is false
or	`or(<expr1>, <expr2>, ...)`	True if at least one expression is true

Conversion Functions

Function	Signature	Description
array	`array('<value>')`	Return array from single input
base64	`base64('<value>')`	Return base64-encoded string
base64ToBinary	`base64ToBinary('<value>')`	Return binary from base64 string
base64ToString	`base64ToString('<value>')`	Decode base64 string
binary	`binary('<value>')`	Return base64-encoded binary of string
bool	`bool(<value>)`	Return boolean version of value
createArray	`createArray('<obj1>', '<obj2>', ...)`	Return array from multiple inputs
dataUri	`dataUri('<value>')`	Return data URI for string
dataUriToBinary	`dataUriToBinary('<value>')`	Return binary from data URI
dataUriToString	`dataUriToString('<value>')`	Return string from data URI
decimal	`decimal('<value>')`	Return decimal number from string. Wrap with string() to preserve precision
decodeBase64	`decodeBase64('<value>')`	Deprecated - use base64ToString()
decodeDataUri	`decodeDataUri('<value>')`	Return binary from data URI. Prefer dataUriToBinary()
decodeUriComponent	`decodeUriComponent('<value>')`	Decode escape characters in string
encodeUriComponent	`encodeUriComponent('<value>')`	Encode URL-unsafe characters. Prefer uriComponent()
float	`float('<value>', '<locale>'?)`	Convert string to float. Supports locale-specific formats
int	`int('<value>')`	Convert string to integer
json	`json('<value>')`	Convert string or XML to JSON
string	`string(<value>)`	Convert value to string. Null becomes empty string ("")
uriComponent	`uriComponent('<value>')`	URI-encode a string
uriComponentToBinary	`uriComponentToBinary('<value>')`	Return binary from URI-encoded string
uriComponentToString	`uriComponentToString('<value>')`	Decode URI-encoded string
xml	`xml('<value>')`	Convert string/JSON to XML. JSON must have single root property

Math Functions

Function	Signature	Description
add	`add(<summand1>, <summand2>)`	Add two numbers
div	`div(<dividend>, <divisor>)`	Divide two numbers (integer division). Divisor cannot be 0
max	`max(<num1>, <num2>, ...)` or `max([<array>])`	Return highest value
min	`min(<num1>, <num2>, ...)` or `min([<array>])`	Return lowest value
mod	`mod(<dividend>, <divisor>)`	Return remainder. Result sign matches dividend
mul	`mul(<multiplicand1>, <multiplicand2>)`	Multiply two numbers
rand	`rand(<minValue>, <maxValue>)`	Random integer, inclusive at start, exclusive at end
range	`range(<startIndex>, <count>)`	Return integer array. Count must be <= 100,000
sub	`sub(<minuend>, <subtrahend>)`	Subtract second from first

Date and Time Functions

Default timestamp format: "o" (yyyy-MM-ddTHH:mm:ss.fffffffK) - ISO 8601. Time unit values: "Second", "Minute", "Hour", "Day", "Week", "Month", "Year".

Function	Signature	Description
addDays	`addDays('<timestamp>', <days>, '<format>'?)`	Add days to timestamp
addHours	`addHours('<timestamp>', <hours>, '<format>'?)`	Add hours to timestamp
addMinutes	`addMinutes('<timestamp>', <minutes>, '<format>'?)`	Add minutes to timestamp
addSeconds	`addSeconds('<timestamp>', <seconds>, '<format>'?)`	Add seconds to timestamp
addToTime	`addToTime('<timestamp>', <interval>, '<timeUnit>', '<format>'?)`	Add time units to timestamp
convertFromUtc	`convertFromUtc('<timestamp>', '<destTimeZone>', '<format>'?)`	Convert from UTC to target time zone
convertTimeZone	`convertTimeZone('<timestamp>', '<sourceTimeZone>', '<destTimeZone>', '<format>'?)`	Convert between time zones
convertToUtc	`convertToUtc('<timestamp>', '<sourceTimeZone>', '<format>'?)`	Convert to UTC
dateDifference	`dateDifference('<startDate>', '<endDate>')`	Return difference as timespan string
dayOfMonth	`dayOfMonth('<timestamp>')`	Return day of month (integer)
dayOfWeek	`dayOfWeek('<timestamp>')`	Return day of week (0=Sunday, 1=Monday, ...)
dayOfYear	`dayOfYear('<timestamp>')`	Return day of year (integer)
formatDateTime	`formatDateTime('<timestamp>', '<format>'?, '<locale>'?)`	Format a timestamp
getFutureTime	`getFutureTime(<interval>, '<timeUnit>', '<format>'?)`	Current timestamp + time units
getPastTime	`getPastTime(<interval>, '<timeUnit>', '<format>'?)`	Current timestamp - time units
parseDateTime	`parseDateTime('<timestamp>', '<locale>'?, '<format>'?)`	Parse timestamp string to ISO 8601
startOfDay	`startOfDay('<timestamp>', '<format>'?)`	Return start of day
startOfHour	`startOfHour('<timestamp>', '<format>'?)`	Return start of hour
startOfMonth	`startOfMonth('<timestamp>', '<format>'?)`	Return start of month
subtractFromTime	`subtractFromTime('<timestamp>', <interval>, '<timeUnit>', '<format>'?)`	Subtract time units from timestamp
ticks	`ticks('<timestamp>')`	Return ticks (100-nanosecond intervals since 0001-01-01)
utcNow	`utcNow('<format>'?)`	Return current timestamp

Workflow Functions

Function	Signature	Description
action	`action()`	Return current action's output at runtime
actions	`actions('<actionName>')`	Return named action's output at runtime
body	`body('<actionName>')`	Return action's body output. Shorthand for `actions('<actionName>').outputs.body`
formDataMultiValues	`formDataMultiValues('<actionName>', '<key>')`	Return array of values matching key in form-data output
formDataValue	`formDataValue('<actionName>', '<key>')`	Return single value matching key in form-data output
item	`item()`	Current item in repeating action over array
items	`items('<loopName>')`	Current item from each cycle in for-each loop
iterationIndexes	`iterationIndexes('<loopName>')`	Index value for current iteration in Until loop
listCallbackUrl	`listCallbackUrl()`	Return callback URL for trigger/action (HttpWebhook and ApiConnectionWebhook only)
multipartBody	`multipartBody('<actionName>', <index>)`	Return body for specific part in multipart output
outputs	`outputs('<actionName>')`	Return action's output at runtime
parameters	`parameters('<parameterName>')`	Return value for workflow parameter
result	`result('<scopedActionName>')`	Return results from top-level actions in scoped action (For_each, Until, Scope)
trigger	`trigger()`	Return trigger output at runtime
triggerBody	`triggerBody()`	Return trigger's body output. Shorthand for `trigger().outputs.body`
triggerFormDataMultiValues	`triggerFormDataMultiValues('<key>')`	Return array of values matching key in trigger form-data
triggerFormDataValue	`triggerFormDataValue('<key>')`	Return single value matching key in trigger form-data
triggerMultipartBody	`triggerMultipartBody(<index>)`	Return body for specific part in trigger multipart output
triggerOutputs	`triggerOutputs()`	Return trigger output. Shorthand for `trigger().outputs`
variables	`variables('<variableName>')`	Return value of specified variable
workflow	`workflow().<property>`	Return workflow details. Properties: name, type, id, location, run, tags

URI Parsing Functions

Function	Signature	Description
uriHost	`uriHost('<uri>')`	Return host value
uriPath	`uriPath('<uri>')`	Return path value
uriPathAndQuery	`uriPathAndQuery('<uri>')`	Return path and query values
uriPort	`uriPort('<uri>')`	Return port value
uriQuery	`uriQuery('<uri>')`	Return query value
uriScheme	`uriScheme('<uri>')`	Return scheme value

JSON & XML Manipulation Functions

Function	Signature	Description
addProperty	`addProperty(<object>, '<property>', <value>)`	Add property to JSON object. Fails if property exists
coalesce	`coalesce(<obj1>, <obj2>, ...)`	Return first non-null value
removeProperty	`removeProperty(<object>, '<property>')`	Remove property from JSON object
setProperty	`setProperty(<object>, '<property>', <value>)`	Set property value on JSON object
xpath	`xpath('<xml>', '<xpath>')`	Find XML nodes/values matching XPath expression

Key Behaviors

•Case sensitivity: contains, replace are case-sensitive. indexOf, lastIndexOf, startsWith, endsWith are case-insensitive.
•Null handling: In logical comparisons, null values become empty strings (""). string(null) returns "".
•Base64: Azure Logic Apps auto-performs base64 encoding/decoding - manual conversion usually unnecessary.
•div() behavior: Integer division when both operands are integers; float result if either operand is float.
•mod() sign: Result sign matches the dividend sign.
•Time zones: Use Windows time zone names (e.g., "Pacific Standard Time").
•Format strings: Use .NET format specifiers for dates and numbers.