For the latest information on Formula Operators and Functions, check out our built-in reference inside the Formula Builder dialog on our web platform.


Whenever you see a "hammer" icon appear next to a field, you can click this icon to launch the Formula Builder.

For example in the Form designer, if you click on a form field, then hover over the Visibility property on the right hand side, you'll see the "hammer" icon appear.




Once in the Formula Builder, the list of available formula functions will appear on the right-hand side of the dialog as a drop down field.


Note: Formula Builder Hints

When you click the drop down, the list of functions displays, and if you mouse over these you should see detailed hints appear next to most of these functions.

These hints explain how to use each function.

When you click a function in the list, you'll see it added to the formula text area with placeholders for the required inputs.


More broadly, we make use of hints heavily through the platform to explain how various functions work.

Whenever you see text with a dashed underline, there's a hint available.

We often put quite detailed text into these hints, so they are always worth checking out.




EXAMPLES OF COMMONLY USED FUNCTIONS - SEE FORMULA BUILDER FOR FULL, UP TO DATE LIST

Contextual Functions

Function

Operator

Example

Notes

current field's answer

.

. < 10.51

 The current answer must be less than 10.51

today

today()

today()

return today's date

now

now()

now()

return a timestamp for this instant


Math Functions

NOTE: You must put a space between your math operators in formulae - e.g. {{price1}}-{{price3}} is not valid, but {{price1}} - {{price3}} is.

Function

Operator

Example

Notes

addition

+

{{price1}} + {{price2}}


subtraction

-

{{price1}} - {{price2}}


multiplication

*

{{price1}} * {{price2}}


division

div

{{price1}} div {{price2}}

You must use the 'div' operator. Using a '/' will not work

greater than

>

{{price}} > 10.51

greater than 10.51, can also be combined with equals: >=

less than

<

{{price}} < 10.51

less than 10.51, can also be combined with equals: <=

rounding

round(value, power)
round({{price}}, 3)
return the rounded value of q1, as in Excel


Text/String Functions

Function

Operator

Example

Notes

concatenated string values

concat(value1, value2, ...)

concat({{name}}, ' with id: ', {{national_id}})

Returns the concatenation of the string values.
Add line breaks with '\n' - e.g. concat('Hello', '\n', 'Goodbye') gives:
Hello
Goodbye

extract a substring

substr(value, start)

substr(value, start, length)

substr('Test',1, 2) = 'es'

returns the sub string beginning at the specified zero-indexed start and runs to the end of the string, unless the optional character length is specified.

length of a string

string-length(value)

string-length('Test')=4

return the length of a non-empty string

concatenate values with a separator

join(separatorString, value1, value2, ...)

concat('The answers are: ', join(', ', {{question1}}, {{question2}}))

returns the concatenation of the answers using the first argument as a separator


Repeatable Group Functions

Function

Operator

Example

Notes

sum repeated values

sum(repeatname)

sum({{prodprice}})

returns the sum of answer values for all repeats of a specified question

concatenate repeat answer with a separator

join(separatorString, repeatvalue)

concat('The products ordered are: ', join('\n', 
{{prodname}}))

returns the concatenation of the repeated answer using the first argument as a separator.
Add line breaks with '\n'.

count repeats

count(repeatname)

count({{products}})

returns a count of a repeatable question/group's occurrences

max of repeated values

max(repeatname)

max({{prodprice}})

returns the maximum answer value from all repeats of a specified question

min of repeated values

min(repeatname)

min({{prodprice}})

returns the minimum answer value from all repeats of a specified question


Logic Functions

Function

Operator

Example

Notes

not

not(expression)

not(selected({{select1}}, 'c'))

as long as 'c' is not selected in the specified Choices question

and

and

selected(., 'c') and selected(., 'd')

both 'c' and 'd' need to be selected in the current prompt

or

or

selected(., 'c') or selected(., 'd')

either 'c' or 'd' needs to be selected in the current prompt

true

true()

true()


false

false()

false()


regular expression

regex(expression)

regex(., '[A-Za-z0-9._%+-]+@[A-Za-z0-9.-]+\.[A-Za-z]{2,4}')

this particular regex checks for a valid email address

equal to

=

. = number('10')

current answer must be equal to 10

conditional

if(condition, a, b)

if(selected({{question1}}, 'yes') and selected({{question2}}, 'yes'), 'yes', 'no')

if true return a, else return b

first non-empty value

coalesce(a, b)

coalesce({{name}}, {{national_id}})

if name has a value, return name, else return national_id

at least X of, at most X of

checklist(min, max, v1, v2, v3, ..., vn)

checklist(min, max, v1, v2, v3, ..., vn)

v1 through vn are a set of n yes/no answers. return true if the count of 'yes' is between min and max, inclusive. min or max may each be -1 to indicate 'not applicable'.


Data Conversion Functions

Function

Operator

Example

Notes

convert to number

number (placeholder or fixed/literal value)

number({{age}})

conversion varies depending on data type of x

convert to string

string (placeholder or fixed/literal value)

string ({{age}})

conversion varies depending on data type of x

convert to date

date (placeholder or fixed/literal value)

date('2011-11-12')

conversion varies depending on data type of x. format is yyyy-mm-dd

boolean from string

boolean-from-string(placeholder or fixed/literal value)

boolean ({{isover30}})

returns true if x is "true" or "1", false otherwise. note that this is different behaviour than boolean(x)

date formatted as string

format-date(placeholder, format)

format-date(today(), 'yyyy-MMM-dd')

returns the date value of the field formatted as defined by the format argument.
The format argument must be a valid .NET date format string. 

Typical format specifiers include: 
yy    - 2 digit year 
yyyy - 4 digit year 
MM  - 2 digit month 
MMM - 3 character abbreviated month 
dd - 2 digit day 

There are many more format specifiers available - click here to see full details.


Choices Functions

Function

Operator

Example

Notes

selected

selected(placeholder, value)

selected({{question}}, 'n')

checks if choices question answer is selected

count selected

count-selected(multi-select placeholder)

count-selected({{multiplechoice}})

return the number of selected answers