# Features

Expression Editor for WinForms allows users to enable the control, simplify creating and editing expressions, apply styles and more. See more demos, documentation, and samples here.

## Content

**ExpressionEditor** provides capabilities for creating, editing, validating, and evaluating expressions. It includes syntax assistance, validation services, and customizable editing that support user-defined calculations and business rules and integrate with data and visualization controls.
The following topics describe ExpressionEditor features:

[Built‑in Functions, Operators, and Constants](/componentone/docs/win/online-expressioneditor/Features/Supported-Functions-Operators-and-Constants) \- Predefined functions\, operators\, and constants support expression construction\.

[Custom Functions](/componentone/docs/win/online-expressioneditor/Features/createcustomfunction) - **ExpressionEditor** supports custom functions that implement application-specific logic.

[Integration with FlexChart](/componentone/docs/win/online-expressioneditor/Features/Integration-with-FlexChart) \- Enables expression\-based chart calculations\.

[Integration with FlexGrid](/componentone/docs/win/online-expressioneditor/Features/Integration-with-FlexGrid) \- Enables expression evaluation on grid data\.

[Integration with MSDataGrid](/componentone/docs/win/online-expressioneditor/Features/Integration-with-MSDataGrid) \- Enables expression evaluation on grid data\.

[Integration with TreeView](/componentone/docs/win/online-expressioneditor/Features/integrationwithtreeview) \- Enables expression evaluation in hierarchical data\.