--- title: "Use the ISDEFINED Function to Return TRUE for Defined Values" slug: "isdefined-function" description: "Learn to enhance model efficiency in Pigment by using ISDEFINED to return BLANK for undefined values and avoid max cardinality issues." updated: 2025-05-30T09:38:39Z published: 2025-08-22T12:00:18Z --- > ## Documentation Index > Fetch the complete documentation index at: https://kb.pigment.com/llms.txt > Use this file to discover all available pages before exploring further. # ISDEFINED function ## ​​​Description Returns TRUE if the given Value is defined, `BLANK` otherwise. > [!TIP] > **Note:** This function is similar to the function [ISNOTBLANK](/v1/docs/isnotblank-function). However it returns BLANK values instead of FALSE, which means that any cells equal to FALSE remain unpopulated. The result is sparse, which means less data, and also less time required to write the result in the database. This prevents max cardinality and timeout errors. ## Syntax `ISDEFINED(Value)` ## Arguments | Argument | Type | Dimensions | Description | | --- | --- | --- | --- | | *Value* (required) | Any | Any | | ## Returns | Type | Dimensions | | --- | --- | | Boolean | Dimensions of argument *Value* | ## Examples | Formula | Result | Description | | --- | --- | --- | | `ISDEFINED(1)` | TRUE | 1 is not `BLANK` | | `ISDEFINED(BLANK)` | `BLANK` | | ## See also Excel: [IS](https://support.microsoft.com/en-us/office/is-functions-0f2d7971-6019-40a0-a171-f2d869135665) Related articles: [ISBLANK](/v1/docs/isblank-function), [IFBLANK](/v1/docs/ifblank-function), [IF](/v1/docs/if-function), [ISNOTBLANK](/v1/docs/isnotblank-function) > [!TIP] > More of a hands-on learner? > > Talk to your Customer Success Manager about downloading the Functions and Modifiers in Pigment Application into your workspace. It includes examples of every formula and modifier in Pigment!