# Eval

### D**escription**‌

> It is recommended to always use Eval for table operations in large datasets for better performance.

The Eval function in [FlowScript ](https://help.novacuraflow.com/development/flowscript)is used to force the evaluation of a [table](https://help.novacuraflow.com/development/flowscript/table) expression.\
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We recommend always using Eval() when dealing with large datasets. It is particularly useful when you need to pre-process or filter data in a table and plan to reuse this processed data later in your script. \
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Eval essentially pre-calculates and stores the results of your table query, making your script more efficient by preventing the need to recompute the same data. 

### **Syntax**

‌The syntax for the Eval function is:

`Eval(table where x < 0)`

#### ‌**Parameters**

table - the table on which the query is to be performed.

### **Returns**

‌The Eval function returns a new table.