All standard Expr functions are listed below, grouped by category. Use the right navigation panel to scroll through functions, or Ctrl+F to find a specific function.

For more information about how functions work, see Notes About Functions.

Notes About Functions

A function may take zero, one or more arguments. Some functions can take an unlimited number of arguments.

Parameter Types

Functions expect certain value types for each parameter. When an unexpected type is provided, Structure will attempt to convert it to an acceptable type. If it can't, the function may consider the value undefined and ignore the value, or it may return an error. 

For example, the MIN function is used to select the smallest number from a series; if the text value "10" is passed as of the parameters, it will convert that to the number 10. If "ABC" is passed, it won't be able to convert that to a number and will return an error.

For more information about how Structure converts values, see Value Conversions.

Undefined Values

A variable used in a formula may have undefined value. Usually it means that the value for an issue is not set – for example, Resolution field will produce undefined value until the issue is resolved. When a function that manipulates values receives an undefined value as its primary argument, the return value will also typically be undefined.


Many functions can also be applied to arrays. When the argument is an array, it will be treated in one of the following ways:

  • Numbers and Text - If the function is expecting a number or text, it will attempt to convert the first element of the array into the appropriate type. If it fails, it will return an error. If there are more than one elements in the array, it will also return an error.
  • Text/Joined - If an array is passed as the parameter, each element in the array will be converted to text and joined together with a comma. (See Text vs. Text/Joined)
  • /Each - If an array is passed as the parameter, the function will be applied separately to each element in the array. The result will be an array with the function applied to each value.