syntax:functions:eval

### Table of Contents

# Eval(text_expression)

Category: Special function

## Description

This function evaluates the *text_expression* argument as an EasyMorph expression.

## Use cases

This function makes it possible to define EasyMorph expressions externally using parameters.

## Arguments

Argument | Type | Description |
---|---|---|

text_expression | Text | An expression in text format to be evaluated. |

**Return value type:** Any (The type of the expression output)

## Remarks

The argument itself must not be an expression with a reference to a column.

In an expression, the eval() function is evaluated first (pre-evaluated) and only then the whole expression is evaluated for every row. Pre-evaluation can be recursive until the final expression doesn't contain the eval() function.

## Examples

eval('1+1') //Returns 2 eval('1' & '+1') //Returns 2 eval('max(1,2)') //Returns 2 eval('[Count]+1') //Evaluated as [Count]+1 eval([Count] & '+1') //Invalid! Column references are not allowed in argument expressions. eval({Param1}) //Parameter references to expressions in text format are allowed. eval("1+" & "eval('1+1')") //Returns 3 (Nesting eval() is allowed.)

syntax/functions/eval.txt · Last modified: 2023/05/16 15:02 by dmitry