> For the complete documentation index, see [llms.txt](https://docs.work-relay.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.work-relay.com/automations/functions-and-formulas/functions-library/logical-functions.md).
# Logical functions
ISBLANK
Analyzes the given expression and returns:
* With one argument: boolean value (**true** if argument expression does not have a value (is empty or does not exist), otherwise returns **false**).
* With 2 or 3 arguments: some expression evaluation result.
**Usage:**
{% code overflow="wrap" %}
```apex
ISBLANK(parameter)
ISBLANK(parameter1, if_true_parameter2)
ISBLANK(parameter1, if_true_parameter2, if_false_parameter3)
```
{% endcode %}
*Replace the parameters with the expressions to evaluate.*
**Example 1:**
{% code overflow="wrap" %}
```apex
ISBLANK({$Variables.someDate})
```
{% endcode %}
Returns **true** if variable "someDate" value is empty (or this variable does not exist at all), and **false** if it has a value.
**Example 2:**
{% code overflow="wrap" %}
```apex
ISBLANK({$Variables.someDate}, '{$System.date}')
```
{% endcode %}
Returns current system date if variable "someDate" value is empty (or this variable does not exist at all), and variable value in other case.
**Example 3:**
{% code overflow="wrap" %}
```apex
ISBLANK({$Variables.someDate}, '{$System.date}', '{Opportunity.closeDate}')
```
{% endcode %}
Returns current system date if variable "someDate" value is empty (or this variable does not exist at all), and value of {Opportunity.closeDate} field if variable has a value.
NOT
Returns **false** for TRUE and **true** for FALSE (inverts result of logical expression).
**Usage:**
```apex
NOT(parameter)
```
*Replace* *`parameter`* *with the expression to evaluate.*
**Example:**
```apex
NOT(CONTAINS({Opportunity.Product_Type__c}, 'part'))
```
Returns **true** when the product type contains 'part'.
IF
Determines if expressions are true or false. Returns a given value if true and another value if false.
**Usage:**
```apex
IF(condition, result_if_true, result_if_false)
```
*Replace* *`condition`* *with the expression to evaluate.*
{% hint style="warning" %}
Condition must return boolean (true or false) result.
{% endhint %}
**Example:**
{% code overflow="wrap" %}
```apex
IF({Opportunity.Items_Number__c} >0, 'In Progress', 'Pending')
```
{% endcode %}
Returns **'In Progress'** when the number of items exceeds zero. Otherwise, returns **'Pending'**.
AND
Returns boolean response: **true** if all parameter values are true, and **false** if one or more values are false.
**Usage:**
{% code overflow="wrap" %}
```apex
AND(boolean_parameter1, boolean_parameter2, ...)
```
{% endcode %}
*Replace the parameters with values or expressions to evaluate.*
**Example:**
{% code overflow="wrap" %}
```apex
AND({Contact.Migrated__c} = 'Yes', {Contact.Trusted__c} = 'Yes')
```
{% endcode %}
Returns **true** when both values equal 'Yes'. Otherwise, returns **false**.
OR
Returns boolean value: **true** if at least one parameter is true, and **false** if all parameters are false.
**Usage:**
{% code overflow="wrap" %}
```apex
OR(boolean_parameter1, boolean_parameter2, ...)
```
{% endcode %}
*Replace the parameters with values or expressions to evaluate.*
**Example:**
{% code overflow="wrap" %}
```apex
OR({$Variables.Exhibition_month__c} = 'MAR', {Partner__c.Exhibition_month__c} = 'APR', {Partner__c.Exhibition_month__c} = 'MAY')
```
{% endcode %}
Returns **true** when `Exhibition_month__c` is set to a spring month.
CASE
Checks given expression value against series of case values. If the expression is equal to one of the case values, returns the corresponding result.
**Usage**:
{% code overflow="wrap" %}
```apex
CASE(value, case1, result1, case2, result2, ..., else_result)
```
{% endcode %}
*Replace:*
* *`value`* *with the field or value you want compared to each specified* *`case`*
* *each* *`case`* *with the data/expression/field for comparison*
* *each* *`result`* *with data/expression/field that must be returned for the proper case*
* *`else_result`* *with the data/expression/field that must be returned when the expression does not equal any case*
**Example:**
Let String\_\_c = 'Plane'.
{% code overflow="wrap" %}
```apex
CASE({Stub__c.String__c}, 'Car' , 'drive', 'Plane', 'fly', 'Boat', 'sail', 'none')
```
{% endcode %}
Returns '**fly**'.
IN
Returns boolean (**true** or **false**) result depending on whether checked value is present in the given list.
**Usage:**
{% code overflow="wrap" %}
```apex
IN(value, list_of_values OR [value1, value2, ...])
```
{% endcode %}
*Replace:*
* *`value`* *with value you need to check in list*
* *`list_of_values`* *with the list to compare value parameter to; or pass list values as separate parameters* *`value1`,* *`value2`, etc*
{% hint style="info" %}
You can also pass combination of lists and separate values as parameters.
{% endhint %}
**Example 1:**
{% code overflow="wrap" %}
```apex
IN({Opportunity.Stage}, 'Closed Lost', 'Closed Won', 'Negotiation/Review', 'Needs Analysis')
```
{% endcode %}
Returns **true** if Opportunity.Stage field value is present in the given set of strings and **false** if it is not.
**Example 2:**
Let Stub\_\_c.String\_\_c = '\["YESTERDAY", "NOW", "TOMORROW"]'.
{% code overflow="wrap" %}
```apex
IN('NOW', JPARSE({Stub__c.String__c}))
```
{% endcode %}
Returns **true**.
**Example 3:**
Let Stub\_\_c.String\_\_c = '\["YESTERDAY", "NOW", "TOMORROW"]' and Stub\_\_c.Area\_\_c = 'NEXT YEAR'.
{% code overflow="wrap" %}
```apex
IN('NEXT YEAR', JPARSE({Stub__c.String__c}), {Stub__c.Area__c}, 'PREVIOUS YEAR')
```
{% endcode %}
Returns **true**.
NOTIN
Returns boolean (**true** or **false**) result depending on whether checked value is NOT present in given list.\
\
**Usage:**
{% code overflow="wrap" %}
```apex
NOTIN(value, list_of_values OR [value1, value2, ...])
```
{% endcode %}
*Replace:*
* *`value`* *with value you need to check in list*
* *`list_of_values`* *with the list to compare value parameter to; or pass list values as separate parameters* *`value1`,* *`value2`, etc.*
{% hint style="info" %}
You can also pass combination of lists and separate values as parameters.
{% endhint %}
**Example 1:**
{% code overflow="wrap" %}
```apex
IN({Opportunity.Stage}, 'Closed Lost', 'Closed Won', 'Negotiation/Review', 'Needs Analysis')
```
{% endcode %}
Returns **true** if Opportunity.Stage field value is not present in the given set of strings and **false** if it is.
**Example 2:**
Let Stub\_\_c.String\_\_c = '\["YESTERDAY", "NOW", "TOMORROW"]'.
{% code overflow="wrap" %}
```apex
NOTIN('NOW', JPARSE({Stub__c.String__c}))
```
{% endcode %}
Returns **false**.
**Example 3:**
Let Stub\_\_c.String\_\_c = '\["YESTERDAY", "NOW", "TOMORROW"]' and Stub\_\_c.Area\_\_c = 'NEXT YEAR'.
{% code overflow="wrap" %}
```apex
NOTIN('NEXT MONTH', JPARSE({Stub__c.String__c}), {Stub__c.Area__c}, 'PREVIOUS YEAR')
```
{% endcode %}
Returns **true**.
INSTANCEOF
Validates if specified value is an instance of a declared type. Returns boolean result (**true** or **false**).
**Usage:**
{% code overflow="wrap" %}
```apex
INSTANCEOF(value, Decimal|Boolean|String|Date|DateTime)
```
{% endcode %}
*Replace* *`value`* *argument with a value you want to validate.*\
*Pass one of the allowed types (Decimal, Boolean, String, Date or DateTime) as second argument.*
**Example:**
{% code overflow="wrap" %}
```apex
INSTANCEOF({$Variables.Result}, Decimal)
```
{% endcode %}
Returns **true** if variable "Result" is a number, and **false** if it is not.