Power Automate Expressions – Quick Guide
- Sivakumar K
- Oct 4, 2025
- 5 min read
Expressions in Power Automate are small formulas that help you transform data, apply conditions, and automate logic within flows. Instead of adding extra steps, you can use expressions to clean data, calculate values, or make decisions directly inside actions.
Here are the main categories of expressions you’ll use most often:
String Functions
Collections / Array Functions
Logical Functions
Math Functions
Date & Time Functions
Conversion Functions
Manipulation Functions
URI Parsing Functions
Workflow / Trigger Functions
String Functions
String functions let you work with text values. They are useful when you need to join names, remove spaces, change text to lowercase/uppercase, or replace certain words. These functions are often used in email formatting, document creation, or cleaning up inputs from forms.
Function | Purpose | Example | Result |
concat(text1, text2, …) | Joins strings together. | concat('Hello ', 'World') | Hello World |
substring(text, start, length) | Extracts part of text. | substring('PowerAutomate', 0, 5) | Power |
length(text) | Gets length of a string/array. | length('Hello') | 5 |
toUpper(text) | Converts to uppercase. | toUpper('abc') | ABC |
toLower(text) | Converts to lowercase. | toLower('ABC') | abc |
trim(text) | Removes spaces from start & end. | trim(' hello ') | hello |
replace(text, old, new) | Replace part of string. | replace('cat','c','b') | bat |
indexOf(text, value) | Finds position of substring. | indexOf('Hello','o') | 4 |
lastIndexOf(text, value) | Finds last position. | lastIndexOf('Hello','l') | 3 |
startsWith(text, value) | Checks if string starts with value. | startsWith('Power','Po') | TRUE |
endsWith(text, value) | Checks if string ends with value. | endsWith('Power','er') | TRUE |
split(text, delimiter) | Splits into array. | split('a,b,c', ',') | ['a','b','c'] |
Collections / Array Functions
Array functions help you work with multiple values at once. You can pick the first or last item, count total items, combine two lists, or filter data. They are useful when dealing with SharePoint lists, Excel rows, or JSON arrays returned from APIs.
Function | Purpose | Example | Result |
createArray(v1,v2,…) | Creates an array. | createArray(1,2,3) | [1,2,3] |
union(array1,array2) | Combines arrays, removes duplicates. | union([1,2],[2,3]) | [1,2,3] |
intersection(a1,a2) | Common values. | intersection([1,2],[2,3]) | [2] |
except(a1,a2) | Values in first not in second. | except([1,2,3],[2]) | [1,3] |
join(array, delimiter) | Join array into string. | join(['a','b'], '-') | a-b |
first(array) | First element. | first([10,20,30]) | 10 |
last(array) | Last element. | last([10,20,30]) | 30 |
skip(array, n) | Skip first n elements. | skip([1,2,3],1) | [2,3] |
take(array, n) | Take first n elements. | take([1,2,3],2) | [1,2] |
Logical Functions
Logical functions are used to set conditions and control the flow path. They let you check if two values match, evaluate true/false outcomes, or run an action only if a condition is met. This is essential in approvals, decision-making, and error handling.
Function | Purpose | Example | Result |
if(condition, trueValue, falseValue) | Inline If. | if(greater(5,3),'Yes','No') | Yes |
equals(v1,v2) | Checks equality. | equals(5,5) | TRUE |
greater(v1,v2) | Greater than. | greater(10,5) | TRUE |
less(v1,v2) | Less than. | less(2,5) | TRUE |
greaterOrEquals(v1,v2) | ≥ | greaterOrEquals(5,5) | TRUE |
lessOrEquals(v1,v2) | ≤ | lessOrEquals(4,5) | TRUE |
and(cond1,cond2) | Logical AND. | and(equals(1,1),equals(2,2)) | TRUE |
or(cond1,cond2) | Logical OR. | or(equals(1,1),equals(2,3)) | TRUE |
not(condition) | Negates condition. | not(equals(1,2)) | TRUE |
Match Functions
Math functions let you perform calculations directly in your flows. You can add or subtract values, multiply or divide numbers, calculate remainders, or even generate random numbers. This is often used in reporting, ID generation, or handling numeric fields.
Function | Purpose | Example | Result |
add(n1,n2) | Add numbers. | add(5,3) | 8 |
sub(n1,n2) | Subtract. | sub(10,5) | 5 |
mul(n1,n2) | Multiply. | mul(5,3) | 15 |
div(n1,n2) | Divide. | div(10,2) | 5 |
mod(n1,n2) | Remainder. | mod(10,3) | 1 |
int(value) | Convert to integer. | int('123.9') | 123 |
float(value) | Convert to float. | float('123.45') | 123.45 |
round(num,decimals) | Round to decimals. | round(12.345,2) | 12.35 |
ceiling(num) | Round up. | ceiling(4.2) | 5 |
floor(num) | Round down. | floor(4.8) | 4 |
rand(min,max) | Random number. | rand(1,100) | 57 |
Date & Time Functions
Date and time functions help you calculate and format time-based data. You can add or subtract days, convert time zones, and format dates for reports or notifications. They’re commonly used in approval deadlines, reminders, and scheduling workflows.
Function | Purpose | Example | Result |
utcNow() | Current UTC datetime. | utcNow() | 2025-10-03T09:00:00Z |
addDays(date, n, format?) | Add days. | addDays('2025-10-03',5,'yyyy-MM-dd') | 08-10-2025 |
addHours(date,n,format?) | Add hours. | addHours(utcNow(),2) | 2025-10-03T11:00:00Z |
addMinutes(date,n) | Add minutes. | addMinutes(utcNow(),30) | +30 minutes |
addSeconds(date,n) | Add seconds. | addSeconds(utcNow(),60) | +1 minute |
subtractFromTime(date,n,unit) | Subtract time. | subtractFromTime(utcNow(),1,'Day') | Yesterday |
ticks(date) | Returns ticks since 1/1/0001. | ticks(utcNow()) | Large number |
formatDateTime(date,format) | Formats date/time. | formatDateTime(utcNow(),'dd-MM-yyyy') | 03-10-2025 |
dayOfWeek(date) | Day of week index. | dayOfWeek('2025-10-03') | 5 (Friday) |
dayOfMonth(date) | Day of month. | dayOfMonth('2025-10-03') | 3 |
month(date) | Month number. | month('2025-10-03') | 10 |
year(date) | Year. | year('2025-10-03') | 2025 |
Conversion Functions
Conversion functions allow you to switch data between formats or types. For example, turning numbers into text, parsing JSON strings into objects, or decoding encoded data. These are helpful when moving data between different systems that require specific formats.
Function | Purpose | Example | Result |
string(value) | Convert to string. | string(123) | "123" |
bool(value) | Convert to Boolean. | bool('true') | TRUE |
json(value) | Parse a string into JSON. | json('{"a":1}')?['a'] | 1 |
base64(value) | Convert to Base64 string. | base64('hello') | aGVsbG8= |
base64ToString(value) | Decode Base64 → string. | base64ToString('aGVsbG8=') | hello |
uriComponent(value) | Encode string for URI. | uriComponent('Power Automate') | Power%20Automate |
uriComponentToString(value) | Decode URI string. | uriComponentToString('Power%20Automate') | Power Automate |
Manipulation Functions
Manipulation functions in Power Automate are designed to work with objects and structured data like JSON or XML. They let you add, update, or remove properties from an object, return the first non-null value, and even extract values from XML using XPath. These functions are especially useful when handling API responses, dynamic data, or custom objects inside your flows.
Function | Purpose | Example | Result |
coalesce(object1, object2, …) | Returns the first non-null value in the list of inputs | coalesce(null, 'Power', 'Automate') | Power |
addProperty(object, property, value) | Returns an object with an additional property/value pair | addProperty(json('{"name":"Siva"}'), 'role', 'Admin') | {"name":"Siva","role":"Admin"} |
setProperty(object, property, value) | Returns an object with the specified property set to a value (updates if exists) | setProperty(json('{"name":"Siva"}'), 'name', 'Kumar') | {"name":"Kumar"} |
removeProperty(object, property) | Returns an object with the specified property removed | removeProperty(json('{"name":"Siva","role":"Admin"}'), 'role') | {"name":"Siva"} |
xpath(xml, xpath) | Returns a node, nodeset, or value as JSON from the provided XML using XPath | xpath(xml('<user><id>123</id></user>'), 'string(//id)') | 123 |
URI Parsing Functions
URI parsing functions in Power Automate are used to extract specific parts of a Uniform Resource Identifier (URI). They allow you to get details such as the host, path, query string, port, and scheme from a full URL. These functions are particularly helpful when working with API calls or web requests, where you often need to break down a URL into its components.
Function | Purpose | Example | Result |
uriHost(uri) | Returns the host (domain) from a URI | uriHost('https://contoso.com:8080/products?id=1') | |
uriPath(uri) | Returns the path from a URI. If no path, returns / | uriPath('https://contoso.com:8080/products?id=1') | /products |
uriPathAndQuery(uri) | Returns the path and query string from a URI | uriPathAndQuery('https://contoso.com:8080/products?id=1') | /products?id=1 |
uriPort(uri) | Returns the port number from a URI. If none, returns the default port (80/443) | uriPort('https://contoso.com:8080/products?id=1') | 8080 |
uriScheme(uri) | Returns the scheme (protocol) from a URI | uriScheme('https://contoso.com:8080/products?id=1') | https |
uriQuery(uri) | Returns the query part of a URI | uriQuery('https://contoso.com:8080/products?id=1') | id=1 |
Workflow Functions
These functions give you details about the flow itself and its trigger. You can fetch information about when the flow was triggered, pull outputs from earlier actions, or check flow metadata. This is helpful for auditing, dynamic references, and debugging flows.
Function | Purpose | Example | Result |
listCallbackUrl() | Returns the URL to invoke the trigger or action. Commonly used to generate a callback endpoint for a specific action. | listCallbackUrl() | |
workflow() | Provides runtime details of the workflow itself such as name, ID, environment, version, etc. | workflow() | { "id": "/workflows/1234", "name": "MyFlow", "type": "workflow", "version": "08585..." } |
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